Area Forecast Discussion
Issued by NWS Burlington, VT-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KBTV 200841
Area Forecast Discussion
National Weather Service Burlington VT
341 AM EST Mon Feb 20 2017
A weak cold front and associated upper level disturbance will
move southward from southern Quebec across Vermont and northern
New York overnight. This system will usher in colder air, along
with a few flurries, mainly across the northern mountains. High
pressure will build eastward from the Great Lakes providing more
seasonable temperatures and dry conditions for Monday and
Monday night. Calm winds and clear skies should make Monday
night the coldest of the week, with overnight lows in the single
digits and low teens. A quick moving low pressure system will
bring a period of rain and localized mixed precipitation to the
region Tuesday afternoon into Tuesday night. Mild temperatures
are then expected for the remainder of the week. The potential
exists for widespread precipitation, mainly in the form of rain,
and breezy conditions with low pressure passing to our west
Friday night into Saturday.
.NEAR TERM /THROUGH TUESDAY/...
As of 958 PM EST Sunday...Late evening update for a few more
minor adjustments, mainly to temps and precip chances. Weak
frontal boundary continues to sag through the North Country
overnight with very spotty drizzle and/or sprinkles reported
across northern surface obs over the past couple hours.
Moisture is really thinning out though as the boundary moves
into central/southern areas with just about no echoes left on
regional radar. Thus, reduced precip chances further for the
rest of the night into Monday, and adjusted temps just a few
degrees to match current observational trends. Otherwise,
remainder of the forecast is intact with cloudy skies slowing
eroding from northwest to southeast through the night, and low
temps mainly in the 20s by sunrise except some upper teens
possible across the Adirondacks. Good night.
Monday and Monday night will feature relatively tranquil
weather as sfc high pressure builds across from the northern
Great Lakes and northern Ontario. Anticipate increasingly sunny
conditions by Monday aftn with highs in the low-mid 30s. Winds
will remain northerly around 10 mph. It appears we`ll have good
radiational cooling conditions much of Monday night, likely
yielding our coldest temperatures of the week. May see some
cirrus moving in from the west toward daybreak, but light winds
and dry deep- layer conditions should yield lows 10-15F in the
Champlain and St. Lawrence Valleys, and in the single digits
elsewhere. May see a few readings below zero across far ern/nern
VT, including around Island Pond, Vermont.
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --As of 339 AM EST Monday...Fast moving warm frontal system with
westerly flow aloft along with narrow and weakening ribbon of
high and mid level moisture will produce a progressive narrow
axis of rain/snow/mix of light precipitation Tue night into
Wednesday. Thermal profiles still showing mostly rain in the
valleys but a mix of precipitation possible in the Adirondacks
and possible freezing rain east of the Green Mountains as colder
air lingers through Wednesday morning. QFP looks to be one to
two tenths in the Dacks and Greens with some downslope shadowing
likely here in the Champlain Valley associated with 850mb winds
of 30 to 45 knots.
Mild surface flow from the south and southwest will continue to
keep temps above seasonal norms with Wednesday highs in the 40`s
and pushing 50 in the Champlain Valley with overnight lows in
the mid to upper 30`s.
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.LONG TERM /THURSDAY THROUGH SUNDAY/...
-- Changed Discussion --As of 339 AM EST Monday...Well above seasonal temperature trend
continues late week into the weekend with developing eastern
CONUS mid/upper level ridging. The next storm system continues
to look like it will come Friday into Saturday with a low
pressure system tracking north and west of our region.
Thursday sees a weak short wave move to the north of the CWA with
some warm moist advection ahead of a weak cold front which
passes through late in the day or Thu eve. Highest chances for
precipitation will be in the north and mainly in the form of
light rain showers. High temperatures will range in the upper
40s to around lower 50`s with 925-mb temps of 3-8C north to
south but cooling below 0C late Thursday night.
Rising 500mb heights forecast along with primary low pressure
tracking north and west of our region through the Great Lakes
Friday through Saturday. Models have backed off potential
secondary low near the NE coast, keeping it much further to the
southeast, opening the door for even warmer conditions for
Saturday before precipitation moves in. ECMWF shows temperatures
in the Champlain Valley to reach nearly 60 degrees, so have
opted to trend closer towards the warmer temps with highs in the
mid 50`s. Things still look like we`ll be affected first by a
warm front Fri evening/Fri night and cold occluded front Sat
night before things quiet down on Sunday as the storm exits the
region. Looks like a mix of precip may fall with the warm front
on Friday followed by mainly windy and mild with rain showers on
Saturday, before changing back to snow showers Sat late night.
Sunday will see a return to closer to normal temps with highs in
the mid to lower 30`s.
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.AVIATION /09Z Monday THROUGH Friday/...
Through 06Z Tuesday...BKN/OVC mix of VFR/MVFR cigs overnight
under light north/northwesterly flow 5 to 10 knots. MVFR most
prevalent at KSLK/KMPV terminals through 12Z and generally SKC
at KMSS. Some evidence of stability aloft may produce scattered
areas of turbulence above 100 AGL overnight. After 12Z skies
gradually trend SKC at all terminals by afternoon under
continued light north/northwesterly flow.
Outlook 06Z Tuesday through Friday...
06Z Tuesday through 21Z Tuesday...VFR/high pressure.
21Z Tuesday through 03Z Wednesday...Mix of VFR/MVFR/IFR in
showers/light mixed precipitation with warm frontal passage.
03Z Wednesday onward...mainly VFR/high pressure. Will see a
warm front approaching from the SW later Friday with increasing
clouds and chances for MVFR rainfall per current indications
late in the day.