FXUS61 KBTV 100034
Area Forecast Discussion
National Weather Service Burlington VT
734 PM EST Sat Dec 9 2017
The North Country will be in between systems tonight with an
upper trough to our west and coastal low pressure to our east.
Later this afternoon and tonight, snowfall associated with the
coastal low will work into eastern portions of the forecast
area, with some light accumulations expected through the night.
Late tonight into Sunday the trough to our west will bring some
scattered snow showers to the region before a more widespread
light snow event is expected Monday night into Wednesday morning
as a low pressure system moves down from Canada.
.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 729 PM EST Saturday...Mesoscale banding as been quasi-
stationary during the past 1-2 hrs, resulting in 3.1" snowfall
per spotter in Hartland, VT. With about three hours of steady-
state conditions upcoming, decided to issue a short-duration
Winter Weather Advisory for Ern Rutland/Windsor/Orange thru 08Z.
Will see vsby below 1 mile at times and slow covered roads
yielding slow travel conditions. Total snowfall amounts up to 5"
expected, mainly across central Windsor into far sern Orange
Counties. Mosaic composite reflectivity at 0015Z showing
mesoscale banding with 20-30dBz returns extending from far swrn
VT newd across srn Rutland/Windsor/ern Orange counties. Band
aligns with axis of mid-level frontogenesis (700-600mb), and
associated UVV will drive best snowfall rates across the far
sern portion of our CWA thru 05Z before best frontogenetic
forcing shifts to the north and east. Vsby generally 1SM or so
in area of snowfall. Anticipate an additional 2-3"...especially
in Windsor county VT thru 05Z or so. Further north and west,
appears progress of the band has halted, and dry low- level air
mass in the Champlain Valley will likely preclude anything more
than a few flurries in the BTV area (ongoing flurries at BTV at
0030Z). Northern extent of steady light snowfall at 0030Z
extends from Newport to Morrisville to Middlebury. A light
accumulation of a coating to 2" is possible across central VT,
with forecast generally on track. Some travel slowdowns can be
expected with the snow accumulations, including along I-91 in
Windsor and Orange counties, and I-89 corridor from MPV
southeast through the remainder of this evening and into the
Lows overnight will be mild, ranging through the 20s under lots
of cloud cover and light winds.
For Sunday, coastal low pressure exits east of the region while
a digging upper trough over the Ohio Valley tonight lifts
northeastward into the New England states. A brisk westerly flow
develops by mid-day with winds in the 10-15mph range and gusts
up to 20 mph, especially across portions of northern New York.
Southwesterly flow combined with some weak elevated instability
will once again produce periods of lake effect snow showers in
the lee of Lake Ontario through the day, mainly affecting the
Adirondacks, but a modest 850mb jet of 25-35kts should be enough
to transport some activity into portions of northern Vermont,
especially in the northern mountains around Jay Peak. Through
Sunday night expect to see a solid 1-3" across southern St.
Lawrence and Franklin counties as well as western portions of
Clinton and Essex counties in New York. Could see localized
amounts of 3-5" in the vicinity of Star Lake and Wanakena.
Eastward across the northern Greens a general dusting to 2" is
expected, with localized amounts up to 4" near Jay Peak. Near
normal temps are forecast for Sunday and Sunday night with highs
in the upper 20s to mid 30s, and lows in the teens.
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 245 PM EST Saturday...Expect a fairly active and cold
pattern to persist through much of next week as the eastern
CONUS remains under the influence of a broad upper trough. Waves
of low pressure will rotate around the trough, keeping the
threat of snow showers in the forecast just about each day. The
steadiest snow will occur on Tuesday as a weak coastal low
develops in conjunction with the digging upper shortwave/clipper
low cross the Great Lakes. Otherwise, expect mostly scattered
snow showers through the week. Temperatures will remain cold
through the period as well, with the coldest readings coming
Wednesday through Thursday. Highs will only be in the teens
these days, while lows will be in the single digits; above zero
in the valleys and below zero in the mountains. There will be
some improvement late in the week as the mid-week wave moves
east, placing the region in southwest flow.
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 245 PM EST Saturday...
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Through 18Z Sunday...A mix of flight categories is expected
through the next 24 hours as coastal low pressure brings snow to
eastern and southeastern portions of the region tonight, and
lake effect snows return to western areas tomorrow. In the
Champlain Valley between the 2 systems KBTV and KPBG will remain
largely VFR through the period. At KMPV and KRUT will bounce
between MVFR and IFR through 07Z before improving to MVFR, then
late in the period back to VFR. KMSS and KSLK begin VFR as
well, but only trend to mainly MVFR after 09Z. Periods of IFR
will be possible at KMSS/KSLK in any heavier lake effects snow
bands, but difficult to predict at this time.
Winds will mainly be light <10kts through 12Z Sunday, then
picking up from the southwest at 10-15kts with some gusts around
Sunday Night: VFR. Chance SHSN.
Monday: Mainly VFR, with local MVFR possible. NO SIG WX.
Monday Night: Mainly VFR, with local MVFR possible. Likely SN.
Tuesday: Mainly MVFR, with areas IFR possible. Likely SN.
Tuesday Night: Mainly MVFR, with areas IFR possible. Chance SHSN,
Wednesday: Mainly MVFR, with local IFR possible. Chance SHSN.
Wednesday Night: Mainly MVFR, with local VFR possible. Chance
Thursday: Mainly VFR, with local MVFR possible. NO SIG WX.
VT...Winter Weather Advisory until 3 AM EST Sunday for VTZ010-012-