FXUS61 KBTV 240820
Area Forecast Discussion
National Weather Service Burlington VT
320 AM EST Tue Nov 24 2020
Drier weather and below normal temperatures are expected
today. A warm front will approach the region Wednesday,
spreading light snow across the North Country, with amounts
generally around an inch or less. Temperatures will warm later
Wednesday and Wednesday night, changing snow to rain by
Thanksgiving. Above normal temperatures are then expected for
.NEAR TERM /THROUGH WEDNESDAY/...
As of 315 AM EST Tuesday...Quiet but cold weather will persist today
as high pressure builds over the region. Lingering upslope snow
showers will continue to slowly wane over the Greens through the
early-mid morning hours. Clouds will gradually dissipate this
morning as well, holding out longest over the Northeast Kingdom.
Brisk northwest winds will abate this afternoon as the high builds
in and the pressure gradient relaxes. Still, cold air advection will
prevail through the day and don`t anticipate temperatures to rise
much, perhaps even falling through the afternoon. Daytime highs will
be in the mid 20s to lower 30s.
The ridge axis shifts to our east overnight, allowing the flow to
turn to the south. MId/high clouds will increase from west to east
overnight as well in response to the onset of warm air advection.
This makes for a bit of a tricky low temperature forecast as both
the turning winds and the increasing clouds will limit cooling
overnight. Lows will likely occur early, especially from the
Champlain Valley westward, and will be in the mid teens to mid 20s.
Some locations in the Northeast Kingdom could see readings closer to
10F, especially if the clouds hold off longer than currently
anticipated. Along with the increasing clouds, we will see a quick
round of snow as warm air advection takes place. The precipitation
will lift northward ahead of the warm front late tonight, spreading
across mainly northern NY after midnight. Snow will become
widespread from the St Lawrence Valley eastward along the
international border into northern VT by 7-9 am Wednesday. This
initial activity will lift north into Canada by noon or so, and
expect many areas will see a break from the snow for a good part of
the afternoon, except perhaps far northern areas and the higher
terrain. Areas from the Champlain Valley westward will see
temperatures warm into the mid and upper 30s, and any lingering
precipitation will change over to rain in the wider valleys during
the afternoon. The colder air will hold in longer in eastern VT, so
precipitation would be more likely to remain snow in these locations
as temperatures will remain in the lower 30s. Can`t rule out perhaps
a bit of wintry mix in the snow/rain transition period, but this
would be localized and brief. Snow accumulations through the
daylight hours Wednesday will be an inch or less, with up to 2
inches in the higher terrain.
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
As of 315 AM EST Tuesday...After a brief lull in precipitation,
Wednesday night will feature increasing chances for valley rain and
mountain snow showers as surface low pressure lifting out of the
Ohio Valley will push a warm front north of the international
border. As the low shifts northeastward through the eastern Great
Lakes it generally weakens with the best mid/upper level forcing
remaining south of the region. Hence, while we continue to highlight
high chances for precipitation, overall QPF will be light and
generally less than a quarter inch with any snowfall amounts less
than an inch. Late Thursday into Thursday night brief ridging aloft
will build over the region with the aforementioned shortwave trough
exiting off the eastern seaboard supporting drying conditions going
through Friday. Mean southwest flow through the period will continue
to support above normal temperatures with highs in the 40s to
potentially low 50s, and lows in the mid 30s to low 40s.
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
As of 315 AM EST Tuesday...Heading into the weekend and early next
week, we`re looking at a potential pattern change as GFS and ECMWF
ensembles are favoring northern Atlantic blocking as noted by a
trend towards a -NAO and +PNA, favoring a western ridge and eastern
trough. A weak northern stream trough lacking any deep moisture will
traverse the Northeast Saturday with perhaps some passing rain/snow
showers followed by high pressure for Sunday. Thereafter is where it
gets potentially interesting as there`s already very good consensus
amongst the operational GFS, ECMWF and GDPS that a deep trough will
develop across much of the eastern CONUS with a ridge of high
pressure amplifying over the western Atlantic. The mid/upper level
steering flow could be as such that developing southern stream
energy might phase with the northern stream trough and track a
strong surface low northward somewhere along the east coast. Time
will tell how this scenario will play out, but it`s nice to see that
there`s perhaps a window of opportunity for some wintry weather.
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
Through 06Z Wednesday...Mostly MVFR cigs across the forecast
area with the exception of KMSS where VFR conditions exist.
Clouds are expected to persist at 1,500 to 3,500 feet until 12z
to 15z. After 15z, high pressure will build into the North
Country and clear out lingering cloud cover. Winds will
generally remain gusty from the west to northwest through
15-18z, then abating to below 10 kt as the high builds over the
Wednesday: Mainly VFR, with local MVFR possible. Chance SHSN,
Wednesday Night: Mainly VFR, with local IFR possible. Likely
SHSN, Likely SHRA.
Thanksgiving Day: Mainly MVFR, with local IFR possible. Chance
SHRA, Chance SHSN.
Thursday Night: Mainly MVFR, with areas IFR possible. NO SIG WX.
Friday: MVFR/IFR conditions possible. NO SIG WX.
Friday Night: Mainly MVFR, with local IFR possible. NO SIG WX.
Saturday: Mainly MVFR, with areas VFR possible. NO SIG WX.
The outage of KPBG ASOS continues as we are awaiting a part to
be delivered. Therefore, there is no estimated time for a return
to service. We appreciate your patience.