008
FXUS61 KBTV 302344
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
744 PM EDT Sat Aug 30 2025
.SYNOPSIS...
Any lingering showers will diminish overnight as largely
dry weather returns through at least Wednesday, with seasonably warm
days and cool nights. A good soaking rain becomes likely towards the
end of the week as a large frontal system approaches from the west.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 135 PM EDT Saturday...Most of the weather of note this
weekend will be through this evening. Breezy west winds,
especially downslope of the Adirondack higher summits but also
east of the Green Mountains, will continue through early
evening. Relatedly there will be a period of 20 to 25 MPH gusts
over northern and broad waters of Lake Champlain before
diminishing tonight. As a well-defined upper level low continues
to spin near Montreal, it will provide plenty of showers in
bands circulating cyclonically/counter-clockwise through far
northern portions of New York and northern Vermont, roughly
north of a line from southern Chittenden County eastward to near
St. Johnsbury. Most rain has been light and steady, with some
localized slightly heavier rain such as here in the Burlington
area, likely due to enhanced surface convergence. Have tried to
keep PoPs near 100% in far northern Vermont, especially in the
vicinity of the northern Green Mountains, where rain will
continue to be steady into the evening. Because the upper level
low is gradually sliding eastward, it should take most of the
steady rain with it, such that where it has been raining chances
will gradually diminish and areas to the south will mainly stay
dry today. Areas that are seeing the steady rain and overcast
skies have stayed quite chilly in the mid and upper 50s, while
temperatures are in the mid and upper 60s in much of south
central Vermont.
However, with such a large extent of clouds and showers, shower
chances will likely linger into tonight before the upper low weakens
and gets absorbed into the exiting trough. In fact, like a winter
storm, some blocked flow with modest northwest winds (about 20 to 25
MPH in the 925 to 850 millibar layer) could keep light rain showers
in the eastern Champlain Valley through midnight. These systems have
strong anticyclonic flow/dry air on the backside, such that wet
conditions will quickly turn dry. Where skies clear, especially
favored in southern portions of Vermont and northern New York, dense
fog should develop in the typical valley locations, with perhaps
a light frost possible in an isolated cold spot. Meanwhile,
areas of fog could develop overnight where it had rained today,
but think enough spokes of cloud cover will prevent significant
radiational cooling that would support frost chances in our
northern areas. After fog dissipates, tomorrow will be a
beautiful day areawide with temperatures climbing into the 70s
with light northwesterly winds. Tomorrow night will be a much
more favorable radiational cooling night, but with a modifying
air mass, it probably won`t be cool enough to see any frost as
minimum temperatures in the coldest spots are likely to fall
into the upper 30s.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 202 PM EDT Saturday...An expansive ridge of high pressure
aloft and at the surface will overlap, ensuring plentiful
sunshine to start the day on Monday. Strong heating and 850
millibar temperatures near 10 Celsius will allow temperatures to
reach the upper 70s to low 80s with superadiabatic lapse rates.
Winds will be very light, but with an easterly component, some
marine air and chances for a thin cloud layer to advect in from
the east will need to be watched to spoil the sunny skies. Nil
PoPs. Fog formation Monday night in the climatologically favored
valleys will be impacted potentially by any stratus, but
generally it should be another good radiational cooling scenario
and low temperatures are likely to be in the mid 40s to low 50s
in most spots.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 135 PM EDT Saturday...Tuesday is expected to be a seasonably
warm day in the 80s with dewpoints bumping up into the mid 50s. With
an upper low meandering across the region and a cool pool aloft, we
should generate about 200-500 J/kg of CAPE across the region.
Surface high pressure will prevent significant low-level forcing,
but there is some upper level divergence and good lapse rates that
should help provide some lift. Orographic lift will likely produce
initial convection that drifts off the mountain ranges, and the NBM
already has a modest handle on this. Mid-level dry air could impede
precipitation from reaching the ground with spotty virga. The upper
low will translate north, and then clearing with sufficiently dry
air should allow seasonable temperatures ranging from the mid 40s to
mid 50s.
Wednesday will be mostly dry as a shortwave ridge builds in with dry
air ahead of an incoming warm front. Another seasonably warm day
with mid 70s to lower 80s will likely unfold. Skies will be
initially clear, and then cloud up later in the day ahead of a high
amplitude upper low.
Probabilistic guidance across all ensemble suites depict an upper
low with normalized anomalies of 3 sigmas below average heights at
500mb as it approaches the Great Lakes, and then likely decays while
shifting east. Ahead of it, deep meridional flow will transport
moisture out of the subtropics northwards very efficiently. The main
cause for spread between different ensemble members is how quickly
the upper low will shift east. These high amplitude features tend to
move a little slower than long range guidance suggests. However,
there`s little evidence of blocking downstream, and so it is
possible that this moves at a modest clip eastward. Early scenarios
depict rain arriving as early as Wednesday night and late scenarios
depict rain arriving as late as Thursday night. Ensemble estimates
for precipitation amounts suggest about a 40-60% probability of
greater than 0.50" between both raw ensembles and NBM. A modest
count showing potentially higher amounts. We need the rain, and this
has a good chance at providing some wetting rain. As the upper low
approaches, we`ll see temperatures become seasonably cool.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...Showers continue to track northwest to
southeast along a weak area of surface convergence between PBG
and SLK. Should a shower move over a terminal, brief MVFR is
possible. Satellite/observations show ample clearing behind
these showers supporting a good set up for areas of fog to
develop overnight. Best chances of IFR are at SLK/MPV under
these conditions with EFK showing some potential at IFR as well.
BTV chances are more conditional and will depend on how much
drainage flow develops; should east winds to 3kts occur, fog
along the Winooski River would likely move over the terminal.
For now, kept patcy fog on station to highlight potential.
Otherwise, RUT/MSS could see some fog, but these spots will be
less favorable - especially RUT with downslope drainage to
around 5kts more likely to develop. After 12Z, VFR conditions
will prevail with winds becoming northerly 5-10kts in general.
Outlook...
Sunday Night: VFR. Areas BR.
Labor Day: VFR. Areas BR.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. Chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
SYNOPSIS...Kutikoff
NEAR TERM...Kutikoff
SHORT TERM...Kutikoff
LONG TERM...Haynes
AVIATION...Boyd
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