FXUS61 KBTV 200823
Area Forecast Discussion
National Weather Service Burlington VT
423 AM EDT Sat Oct 20 2018
A changeable weather pattern is expected this weekend, as a
series of cold fronts impact the North Country. Temperatures
will be near normal today, but trend back below normal for
Sunday into early this upcoming week. Each front will be
accompanied by a chance of rain showers and mountains snow
showers, along with periods of breezy conditions. The overall
coverage of precipitation will become mainly terrain focused on
Sunday, before cold high pressure builds into the region by
Monday. Additional precipitation chances occur toward midweek
with below normal temperatures prevailing.
.NEAR TERM /THROUGH SUNDAY/...
As of 358 AM EDT Saturday...Changeable weather anticipated the
next 12 to 24 hours as a series of s/w`s and cold fronts swing
across our fa. Water vapor shows potent 5h vort approaching the
slv, but best deep layer moisture is suppressed to our
south...as pw analysis shows values near 0.60. These quickly
drop to 0.30 as well defined mid/upper level dry slot across the
central Great Lakes advects across our cwa today. Thinking
current band of rain showers will slowly fall apart across the
slv/dacks this morning, as s/w energy weakens and best moisture
is continued to be suppressed to our south. Have mentioned
likely pops west and taper to schc/chc pops further east, with
highest qpf amounts of 0.10 to 0.20 across the slv. Given breezy
southwest winds of 35 to 45 knots, thinking downslope shadowing
will occur across the cpv with minimal precip expected. Clouds
coverage will be tricky today, with a little of everything
possible, especially in the cpv. Thinking mostly cloudy skies
prevail in the mountains. Temps will range from near 40f summits
to mid/upper 50s warmer valleys, with summit temps falling back
into the upper 20s and lower 30s by 21z today, as 850mb caa
develops. Secondary front surges across our cwa this evening and
helps push 925mb temps below 0c by 06z. This secondary front is
associated with some mid level moisture, but best forcing
associated with 5h energy passes to our south, so any precip
will be light and mainly trrn focused in northern dacks and
mountains of Vt. Have continued to mention chc pops with thermal
profiles supporting snow levels down to 1500 feet by morning,
with very limited accumulation anticipated. Maybe a dusting to
0.5 above 2000 feet in the northern dacks and parts of the green
mtns. Lows range from the upper teens summits to mid/upper 30s
cpv and lower ct river valley tonight. A cold and breezy day is
anticipated on Sunday with moderate low level cold air advection
prevailing. 850mb temps are a degree or two warmer than
previous cold spell, with values near -9c or -10c, so have highs
mainly lower/mid 20s summits to l/m 40s warmest valleys.
Soundings support northwest winds 15 to 25 knots with localized
gusts up to 30 knots possible in favorable northwest downslope
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
As of 415 AM EDT Saturday...Sunday night will be cold with
temperatures dropping below freezing areawide. Temperatures will
generally be in the 20s, with some teens in the coldest spots.
It will be warmest along the shores of Lake Champlain. Surface
high pressure ridge will be building into our region from the
South. 850 temps will be around -10 C. These temperatures will
be almost 10 degrees below seasonal normals for the second half
of October in Northern New York and Vermont. On Monday high
pressure ridge will slide eastward and Southwesterly flow will
develop. With that we may see some lake effect snow showers
making it into the Southern St Lawrence Valley and Adirondacks.
Progressive upper level flow will be in place and will have
several upper level shortwaves passing overhead. Monday high
temperatures will also be below seasonal normals, generally mid
30s to mid 40s with some colder spots in the higher elevations.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 415 AM EDT Saturday...On Monday night into Tuesday an
upper level shortwave trough will be approaching from the west
and we`ll have our next chance of precipitation. There`s a weak
surface low associated with this upper level feature, not a lot
of forcing so don`t expect any significant precipitation. This
upper level trough will be very slow moving, and finally move
east of our region on Thursday. Thursday through Saturday then
looks drier with surface high pressure building into the area.
Temperature will remain below normal through the extended
portion of the forecast with highs in the 40s and lows in the
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
Through 06Z Sunday...A series of fronts will move across our
taf sites today, with best chance of light rainfall occurring at
mss/slk. Low level moisture profiles will continue to increase
with ifr cigs trending toward mvfr at slk by 09z this morning.
Elsewhere, mainly vfr cigs prevail associated with breezy
southwest winds of 15 to 25 knots. These winds will gradually
shift to the west and northwest by this evening with precip
becoming mainly trrn focused and scattered in nature.
Saturday Night: Mainly VFR, with local MVFR possible. Chance
SHRA, Chance SHSN.
Sunday: Mainly VFR, with local MVFR possible. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: VFR. Slight chance SHRA.
Monday Night: Mainly VFR, with local MVFR possible. Chance SHRA,
Tuesday: Mainly MVFR, with areas VFR possible. Chance SHRA.
Tuesday Night: MVFR/IFR conditions possible. Chance SHRA, Chance
Wednesday: MVFR/IFR conditions possible. Chance SHRA.
A Lake Wind Advisory will continue today with south winds
generally remaining in the 20-30kt range. A cold front will
sweep across Lake Champlain during the mid-day hours, resulting
in a westerly wind shift by this afternoon, with winds
decreasing slightly into the 10-20kt range behind the cold
front. Waves will be 2 to 4 ft.