FXUS61 KBTV 211305
Area Forecast Discussion
National Weather Service Burlington VT
905 AM EDT Sun Oct 21 2018
Surface high pressure will ridge into the Northern New York and
Vermont area today and tonight. There is a chance for some lake
effect snow showers in the Southern St Lawrence valley and
Northern Adirondacks on Monday. An upper trough moves across the
North Country Tuesday and Wednesday bringing more scattered
light rain and snow showers. Temperatures will be below normal
over the next 8 days with maximum temperatures only in the 40s.
.NEAR TERM /THROUGH MONDAY/...
As of 905 AM EDT Sunday...Based on satellite imagery there is
quite a bit of cloud cover over the area and upstream as well.
Combined with cold air advection through much of the day that
will likely hold in more clouds and have adjusted the forecast
to go with more clouds persisting throughout the day today.
Rest of forecast in good shape and remains unchanged.
High pressure ridges into the area today and mainly dry
conditions are expected for today and tonight. Winds will be a
bit gusty out of the Northwest, though we have limited low level
moisture so don`t expect too much in the way of showers.
Tonight will be cold, though clouds will keep temperatures from
radiating out to their full potential, as well as some gradient
winds. Have mentioned frost in the grids regardless. If models
trend more clear and calm with the forecast for tonight, we
could need a frost or freeze headline for the Champlain valley
Sunday night. On Monday, aforementioned surface high will slide
eastward and a weak low pressure system will approach from the
Northern Great Lakes. Flow will turn more southwesterly between
these two features, and some light lake effect snow showers are
expected in the Southern St Lawrence Valley and Northern
Adirondacks. Temperatures remain cold with highs remaining in
the 40s and increasing cloudiness across the area.
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
As of 230 AM EDT Sunday...At the onset of this period, SW flow
aloft over eastern Great Lakes will allow for some lake effect
rain showers which will add some moisture to the atmosphere and
possibly bring some rain showers into portions of northern NY
ahead of next strong shortwave.
Another strong NW shortwave and associates surface low and cold
front drop across the Great Lakes and rotates across New
England/NY Tuesday-Tuesday evening. Somewhat moisture starved
but decent lapse rates with cold pool aloft thus expect
scattered showers with temps cold enough aloft for a mountain
snow shower/two late Tues-Tues ngt.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 230 AM EDT Sunday...As mentioned above front has largely
passed area by Tuesday night but still some instability and some
deeper moisture being wrapped around 700mb low across eastern
Quebec/ME for some valley rain/mountain snow showers.
Deep cyclonic flow persists Wednesday between upper trough axis
and surface low east and upper/surface ridge across Northern
Central CONUS thus favorable upslope flow will bring best shot
of mountain snow/rain showers.
There is a block in the North Atlantic not allowing the upper
trough to shift east anytime soon but by Thursday and into the
weekend it slides just enough away to allow slight a slightly
more wnw upper flow and surface high to dominate. Pretty quiet
for this period.
It will be a cool period with daytime highs in the L-M40s
Wed/Thu/Fri, some 30s in cold spots, moderating with time by the
weekend. Overnight lows in the 30s Tues ngt falling into the
20s/some teens Wed/Thu nights and modifying back into 20s/30s
by Friday night-Saturday morning.
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
Through 12Z Monday...MPV and SLK still have some MVFR around,
though expect conditions to improve by about 15z. VFR conditions
are then expected from this afternoon onwards as high pressure
continues to ridge into the area. NW gusty winds today will
Monday: VFR. Areas frost, Slight chance SHRA.
Monday Night: VFR. Chance SHSN, Slight chance SHRA.
Tuesday: Mainly VFR, with local MVFR possible. Likely SHRA.
Tuesday Night: MVFR/IFR conditions possible. Chance SHRA, Chance
Wednesday: Mainly MVFR, with local IFR possible. Chance SHRA,
Wednesday Night: Mainly VFR, with areas MVFR possible. Slight
Thursday: Mainly VFR, with local MVFR possible. Slight chance
SHRA, Slight chance SHSN.
A Lake Wind Advisory continues through this morning with northwest
winds at 15 to 25 knots. This afternoon winds decrease to 10 to
20 knots. Waves will continue in the 2 to 4 foot range before
decreasing to 1 to 3 feet later this afternoon. Choppy
conditions will continue through this morning, especially on
the east side of the lake.