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FXUS61 KBTV 090310

Area Forecast Discussion
National Weather Service Burlington VT
1010 PM EST Sun Dec 8 2019

A light wintry mix will develop across the North Country later tonight
with some light ice and snow accumulation possible by early 
Monday morning. This will cause areas of slippery travel during 
the Monday morning commute, especially east of the Green 
Mountains and deeper valleys of the northern Adirondacks. As 
temperatures climb into the upper 30s to mid 40s by midday 
Monday, any mix precipitation will change occasional rain 
showers by Monday afternoon. Breezy southerly winds will 
continue, before a wind shift and cooler air arrives for Tuesday
into Tuesday night. Rain showers will change back to snow, but 
any accumulations will be light and mainly over the higher 


As of 1010 PM EST Sunday...Still awaiting arrival of light 
precipitation in parts of Northern New York and Northeast 
Kingdom of Vermont as radar data indicates virga with increasing
reflectivity. While we slowed the onset time of precipitation 
we are dtill on track for higher chances of light mixed 
precipitation to develop, especially after 4 AM. Slow but steady
warm advection has been bringing a gradual rise in temperature 
and dew points. We increased forecast dew points and 
temperatures over the next few hours ahead of precipitation in 
accordance with the latest guidance, which seems to account for
temperatures that are slightly higher than previous forecast. 
Rest of forecast in good shape and no other changes needed at 
this time.

Previous Discussion...
A light wintry mix is anticipated to impact parts of the dacks 
and portions of central/eastern and northern VT tonight into 
Monday morning, with areas of slippery travel expected during 
the Monday morning commute. Have issued sps for the potential 
hazardous driving conditions across these areas, but any ice 
accumulation will be minor and only a couple hundreths of an 
inch and snowfall generally under an inch. 

Water vapor shows deep broad southwest flow prevailing acrs the
Great Lakes into the NE Conus with general waa continuing as better
moisture profiles advect toward our fa. The combination of weak
embedded 5h vort over the Ohio Valley, better 850 to 500mb moisture,
and continued lift provided by favorable 850 to 700mb fgen forcing
will produce a period of light wintry mix acrs portions of our cwa.
This initial axis of moisture will be mainly confined to the
northern Dacks into the mountains of central/northern VT, while
strong 925mb to 850mb southwest winds of 45 to 55 knots will limit
qpf/pops in the CPV. Also, best forcing/moisture is focused over our
northern fa, with very limited qpf/pops expected over
Rutland/Windsor Counties. Have this north to south gradient
integrated into the fcst. Temps are tricky with breezy
south/southwest winds and clouds prevailing overnight, so anticipate
wider valleys of cpv/slv temps hold steady or increase toward 40f by
12z Monday. Meanwhile, cold air will remain trapped in the
deeper/protected valleys with lows mainly in the 20s, especially
east of the Greens. Soundings show complex low level thermal
profiles with each model solution providing a different ptype
solution. However, expecting warm layer to develop btwn 925mb and
850mb on strong southwest winds, with temps warming into the 1-3c,
while cold pocket around 950mb of -2c to -3c supports the mix of
some sleet. Have utilized a multiple model blend top down mixed
precip approach, which indicates a mix of snow/sleet, changing to
sleet/freezing rain, before changing to all rain by midday Monday.
However, pockets of freezing rain are likely even with sfc temps in
the mid 30s, due to very cold ground temps, especially with readings
this morning in the 5 to -5f. Will issue sps to highlight the
expected slippery traveling conditions acrs the dacks and east of
the Greens. Periods of gusty south/southwest winds continue through
tonight, especially in aligned valleys where deeper mixing occurs.

Monday, expecting areal coverage of precip to increase btwn 15-21z,
especially acrs central/southern VT and upslope portions of the
dacks. Given very strong 925mb to 850mb wind fields, anticipating
qpf will be highly trrn driven with greatest amounts in the se
upslope regions of the central/southern greens and eastern dacks.
Meanwhile, downslope flow will limit qpf acrs the cpv. Have tried to
show a sharp range in values from 0.15 near PBG to 0.25 BTV to 0.50
SLK and near 1.0 favorable se upslope areas. It should be noted that
even with air temps mid/upper 30s, ground temps are cold, given
recent cold spell, so areas of freezing rain with cold pavement
temps could linger into mid morning on Monday. Pockets of slippery
travel is anticipated, especially on any untreated road surfaces and
bridges. Temps finally warm well into the 40s and threat for icing
ends by aftn. Additional showers and very mild temps prevail on
Monday night as cwa is well established in warm sector. Areas of fog
are possible as warm/moist air advects over cold snow pack,
especially deeper/protect valleys. Given, qpf/snow melt not
anticipating any hydro related issues, but Otter Creek could
approach flood stage according to the latest NERFC forecast.


As of 349 PM EST Sunday...A cold front will pass from west to east
Tuesday morning causing temperatures to decrease throughout the day.
Highs are expected mid- morning in the 40s, with lows Wednesday
morning in the teens and low 20s. Winds will be brisk Tuesday 
morning at 10-15kts with gusts near 20-25kts, but will decrease 
Tuesday night and remain below 10kts for Wednesday. A chance of 
rain showers exists across the forecast area Tuesday, especially
within the higher terrain of northern New York. Additional 
rainfall of a few hundreths is forecast during this time. As 
midlevel dry air settles in behind the front Tuesday afternoon, 
chances of precipitation dwindle, though a chance of snow 
showers persist Tuesday evening and overnight as lake moisture 
is advected into the region.


As of 349 PM EST Sunday...Wednesday will bring a lingering chance of
snow showers across the region due to lake moisture coupled with
upper level short wave energy. This will result in snow
accumulations of less than half an inch Wednesday afternoon. High
pressure then settles across the area Thursday allowing for some
sunshine, though remaining chilly with highs in the teens and low
20s, and lows Friday morning in the single digits. Friday becomes
cloudy again as we enter a regime of warm air advection ahead of an
approaching low pressure system, which is expected to bring precip
across the area Saturday. High temperatures at the end of the week
are expected to be in the high 30s and low 40s.


Through 00Z Tuesday...Wind shear will continue to be an issue
across much of the area through about 12z Monday with a lull in
the winds between 12z and 18z on Monday and then a second low
level jet moving in and creating low level wind shear once again
across the area from 18z to the end of the period. During both
periods of low level wind shear winds will be from the south at
2000 feet at speeds in the 40 to 50 knot range. This will result
in areas of moderate to severe turbulence. Otherwise looking at
VFR conditions with respect to ceilings and visibilities through
about 12z. After 12z ceilings will be lowering into the MVFR
category and possibly into the IFR category after 20z.
Visibilities will be lowering as precipitation becomes
widespread after 12z. Precipitation prior to 12z will be light
and may be a mix of snow...sleet...freezing rain...and rain
before becoming all rain between 12z and 18z. Visibilities will
lower into the MVFR category after 12z and could briefly reach
the IFR category.


Monday Night: Mainly MVFR, with local IFR possible. Chance SHRA.
Tuesday: Mainly VFR, with local IFR possible. Chance SHRA, Chance
Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHSN.
Wednesday: VFR. Chance SHSN.
Wednesday Night: VFR. Slight chance SHSN.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.


A period of very strong winds will impact Lake Champlain tonight
and continue through Monday. South winds of 25 to 35 knots and
frequent gusts to 40 knots will occur tonight and creating very
difficult boating conditions...especially on the north end of
the lake where waves of 5 to 7 feet will occur because of the
strong winds. Winds will eventually taper off a bit on
Monday...but remain in the 20 to 30 knot range and waves of 4 to
6 feet.




NEAR TERM...Kutikoff/Evenson/Taber 

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