Williston, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

241
FXUS61 KBTV 111438
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1038 AM EDT Fri Apr 11 2025

.SYNOPSIS...
Precipitation moves out this morning, and mostly dry and seasonable
conditions should prevail for the rest of the day. A low pressure
system will move through on Saturday and it will bring elevation
dependent rain and snow for much of the region. The highest
accumulations will be in southern Vermont, where a few inches are
possible. Drier weather returns to end the weekend and start next
week, and temperatures will increase significantly.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 1021 AM EDT Friday...A cool and cloudy day prevails acrs
much of the fa with some light rain showers over the SLV. Water
vapor shows mid lvl dry slot overhead, but llvl moisture remains
in the sfc to 750mb layer, which has resulted in plenty of
clouds. Given the closeness of the mid/upper lvl trof and
south/southeast flow feel clouds wl persist most of the day,
with maybe a few breaks acrs the CPV and lower CT River Valley
this aftn as moisture profiles thin a little. Temps wl remain
cool for mid April with highs upper 30s to upper 40s with lower
50s possible near BTV.

Based on water vapor/radar trends associated with developing
area of low pres along the mid Atlantic Coast, we may need some
winter wx advisory for parts of the region tonight into
Saturday. More after examining all 12z data.

Previous Discussion...Light showers continue across much of the
region, but they have begun to decrease in coverage and
intensity. Snow levels are around 1,000 feet, with lower values
in southern areas where precipitation has been heavier and
higher values in northern areas where precipitation has been
lighter. However, light precipitation rates and above freezing
temperatures are limiting accumulations to the highest terrain
and areas with existing snowpack. Up to around an inch is
possible in the higher terrain of southern Vermont, with lower
totals elsewhere. This precipitation gradually falls apart as
the night goes on and into the morning. Dry conditions should
prevail for much of today and tonight, and there could even even
be a few breaks in the clouds. A few showers may linger over
parts of the ST. Lawrence Valley, but even there, conditions
should be mostly dry. Temperatures will be pretty seasonable,
with highs in the 40s and low 50s. These conditions will quickly
melt any snow that fell overnight.

A surface low moves up from the south and toward the region on
Saturday. The models are finally coming into somewhat of an
agreement with the setup and timing. Precipitation looks to arrive
in southern areas Saturday morning and the band will progress
northward during the day. Initially, the band looks to have strong
dynamics and it should be able to produce a period of heavy
precipitation over southern Vermont. Temperatures will be in the 30s
at the onset and there should be strong dynamical cooling with this
band, so most of southern Vermont should be able to see a period of
snow Saturday morning. Temperatures in the immediate valleys will be
marginal, so minor accumulations are possible there in the heaviest
band, before snow levels rise once it moves out and temperatures
rise several degrees above freezing. Any snow there would would
likely melt soon after it stops falling. In the higher elevations,
lower temperatures will allow for more efficient accumulations, and
it may remain cold enough for the precipitation to remain as snow
after the heaviest band passes through, and a few inches are
becoming likely there. The snow will be heavy and wet, though there
should not be enough for power outages to occur. The band will
weaken as it travels northward and it will likely not make it all
the way to the St. Lawrence Valley. Temperatures in northern areas
that do not see any precipitation will make a run at 50. In northern
areas that do see the precipitation, it will likely be light enough
and not have enough dynamics to lower snow levels much, so any snow
will likley be confined to the highest terrain. However, the onset
of the precipitation should still lower temperatures by several
degrees.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
As of 346 AM EDT Friday...Upper-level low pressure will be positioned
just off the US East Coast Saturday night into Sunday. Compared to
yesterday, trends indicate a slight westward shift regarding an
offshore surface low. Ensembles remain entrenched in their own camps
with each contributing almost exclusively to a single cluster and
little to others. Despite this and the overall westward track shift,
ensemble means have shifted snow south or east. The reasoning for
this is that as low pressure heads towards the Gulf of Maine a lack
of upper level support and better vorticity on the south side of
this feature will cause precipitation to gradually decay across
Vermont and northern New York. Enough GEFS members maintain activity
in Sunday, along with NBM probabilities of measurable precipitation
in the 20- 50% range over eastern Vermont. There could still be
lingering activity Saturday night and Sunday; however, dry air will
encroach from the west as a deep-layer ridge builds east. This
should result in a fairly pleasant Sunday afternoon with gradual
clearing, decreasing north winds, and temperatures into the 50s,
perhaps touching 60.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 346 AM EDT Friday...Ridging will be well established by Monday
as low pressure will track along the Great Lakes. A dry warm frontal
passage will take place with winds switching out of the south
midday, and this should push temperatures into the upper 50s to mid
60s. Winds don`t increase to anything too fast as relative humidity
settles to about 35-45% in the afternoon. Late Monday evening into
the overnight hours, an occluded front will zip east. There may be
some convective elements with marginal elevated instability.
Overall, confidence is not high enough to place any thunder in the
forecast. Forecast timing has sped up with the ensuing cold front
racing east during the afternoon Tuesday. Cold air will rush
southeast, and our high temperature may take place late Tuesday
morning or early afternoon before it comes crashing down. With a
strong upper low, multiple vorts tracking near the region, and
sufficient moisture, scattered to numerous (30-80 PoPs) rain or snow
showers will take place Tuesday night into Wednesday, especially for
northern mountains. It will be a chilly Wednesday, with temperatures
in the mid 30s to mid 40s and a brisk northwest wind.

Flow remains progressive. Next Thursday appears dry as the upper low
pulls away. Despite the ridging and decreasing north winds, it`ll
take a bit of time to moderate this air mass. A quiet and cool day
is presently on tap for next Thursday.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
Through 12Z Saturday...Lingering precipitation should mostly taper
off this morning, except at MSS where showers may continue on and
off for much of today. Ceilings will gradually rise during the day,
and most terminals should be VFR by afternoon. MSS looks to be an
exception, and while ceilings should eventually rise a bit, they
will likely stay low MVFR due to the moisture from the lingering
precipitation. Any lingering showers should not be heavy enough to
significantly reduce visibilities. Winds will generally be light and
southerly today, before becoming more variable and terrain driven
tonight. A period of snow is possible at RUT late tonight and early
tomorrow morning, and it could be heavy enough to significantly
reduce visibilities.

Outlook...

Saturday: Mainly VFR, with local MVFR and IFR possible. Chance
RA, Likely SN.
Saturday Night: Mainly VFR, with areas MVFR possible. Slight
chance SHRA.
Sunday: Mainly VFR, with areas MVFR possible. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: Mainly VFR, with local MVFR possible. NO SIG WX.
Monday Night: Mainly VFR, with local IFR possible. Likely SHRA.
Tuesday: Mainly MVFR, with local IFR possible. Likely SHRA.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Myskowski
NEAR TERM...Myskowski/Taber
SHORT TERM...Haynes
LONG TERM...Haynes
AVIATION...Myskowski