FXUS61 KBTV 121733
Area Forecast Discussion
National Weather Service Burlington VT
133 PM EDT Sat Oct 12 2019
A decaying frontal system approaching from the Great Lakes will
bring a few light showers to the area this afternoon into early
tonight, mainly across northern New York. The next chance for
widespread rainfall isn`t expected until next Wednesday.
Temperatures through mid-week will be near seasonal norms with a
brief cooldown expected Thursday and Friday.
.NEAR TERM /THROUGH SUNDAY/...
As of 1034 AM EDT Saturday...Minor updates as of late morning,
mainly to hold pesky low stratus into early afternoon across
eastern VT and to raise temperature maxima in the immediate
Champlain Valley by 1-2 degrees. The rest of the forecast and
overall met reasoning remain on track. Have a great day!
Forecast on track with just some minor updates to skycover and
hourly temperature forecast to better match observations.
Previous discussion...Mid-level clouds from Subtropical
Storm Melissa will pivot through New England this morning as
the system remains quasi stationary just southeast of Benchmark
(40N 70W). As surface high pressure over the Canadian Maritimes
weakens and moves east, a progressive pattern will redevelop
over the western Atlantic and the subtropical storm will be
carried out to sea. Attention then turns to our west, where an
expansive occluded low remains over the northern
Plains/northwestern Great Lakes Region. This system will send a
decaying frontal occlusion eastward through the day today. By
the time the boundary reaches the BTV forecast area, it will be
well removed from the upper support/best dynamics further west.
Consequently, expecting no more than some increased cloud cover
from the west today and a few light showers moving through this
afternoon into early overnight tonight. Best chances for
measurable precipitation, albeit very light (less than 0.05
inches), will be in the Saint Lawrence Valley and northern
Adirondacks. Elsewhere, looking at a mainly dry forecast with
nothing more than a few sprinkles anticipated. Highs will again
be in the upper 50s to mid 60s today, lows tonight generally in
High pressure will build in Sunday, providing a beautiful fall
day. Sunny skies are expected with light winds and continued
highs in the upper 50s to mid 60s.
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
As of 339 AM EDT Saturday...Sunday night will start off quiet and
mild with weak ridging along the New England coastline. As the night
progresses, this surface high will begin to be displaced eastward
while a well wrapped up low pressure begins to drift toward the
North Country. We will see weak moisture advection through the
overnight period which should begin to increase cloud cover but the
main moisture axis will be directed to our south and east. As we
approach Monday morning, the aforementioned low pressure system will
be moving across James Bay with a weak cold front approaching the
region from the west. With the main moisture axis well to our south
and the surface/upper level low well to our north, we don`t have a
lot going for precipitation chances. However, some weak cold air
advection is evident at the 925 mb and 850 mb layers which may be
conducive for some weak instability showers to develop with the
frontal passage. Have kept the general chance to slight chance
wording going for the time being with the highest chances across
northern New York. As we head into Monday night, the 850 mb 0 degree
isotherm will dip into northern New York and northern Vermont
briefly as showers begin to exit the region. This could yield a few
snow flurries to maybe a dusting at higher elevations in the
Adirondack and Green Mountains.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 339 AM EDT Saturday...Tuesday will be the nicest day of the
upcoming week albeit a touch on the chilly side. Surface high
pressure will build across the region which will yield mostly clear
skies, but we will remain under the influence of the upper
level low through much of the day. This will continue to filter
cooler temperatures down into the North Country from Canada and
result in high temperatures struggling to climb into the lower
to upper 50s. This surface high pressure will be transient and
will push offshore just after midnight as we head into
Wednesday. At this point, another low pressure system, will
track across the Great Lakes. By Wednesday morning, everything
begins to get a bit messy across the Northeast. While the
primary surface low is expected to track just to the north of
the international border, a secondary low will form at the
triple point of the front associated with the primary low. Based
on all of the model guidance, which is actually in extremely
good agreement, the secondary low ends up becoming to main show
as it develops just of the New England Coast. The storm track is
actually almost identical to many of our snow producers from
the previous winter but it`s a touch too early in the season to
be thinking about that.
The nose of the upper level jet associated with the parent low will
push across the North Country Wednesday afternoon and be the focus
for an intense band of rainfall with strong frontogenetical forcing
present on all deterministic guidance. The good news is that the
precipitation will be moving eastward quickly but many locations
could easily see a half inch to an inch of rainfall if not a little
more. As the new low off the New England Coast develops, the best
forcing and moisture will shift eastward toward Maine which will
leave the North Country largely on the dry side. However, upslope
flow coupled with cold air advection will likely keep some shower
activity going across the mountains of Northern New York into
Thursday. There is a chance for some accumulating snowfall at the
summits of the Adirondacks in New York but otherwise it will likely
be just a cold rain with highs in the upper 40s to mid 50s. Deep
layer ridging will then begin to develop across the North Country on
Friday which will bring an end to the wetter period for a brief
period of time while also bringing back above normal temperatures to
the region heading into the following weekend.
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Through 18Z Sunday...Weak frontal boundary to push through the
area this evening with little fanfare other than a few showers,
mainly KMSS and KSLK in the 18-22Z time frame. Mainly dry at
Vermont terminals. Cigs BKN/OVC and generally VFR, through a
period of MVFR likely at KMSS/KSLK from 21-03Z or so and
possibly at KMPV later tonight from 04-09Z behind the front.
Winds variable and mainly less than 10 kts through the forecast
Sunday Night: VFR. NO SIG WX.
Columbus Day: VFR. Slight chance SHRA.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. Slight chance SHRA.
Wednesday: Mainly VFR, with local MVFR possible. Definite RA.
Wednesday Night: MVFR/IFR conditions possible. Chance RA, Chance
Thursday: Mainly MVFR, with local IFR possible. Chance SHRA.