760
FXUS61 KBTV 172010
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
410 PM EDT Wed Jun 17 2026
.WHAT HAS CHANGED...
As of 242 PM EDT Wednesday...
A Wind Advisory has been issued for the entire region outside of
Orange, and eastern Windsor Counties in Vermont, from 8 AM to 8 PM
Tomorrow. Winds will gust between 45 and 55 MPH, especially in the
Champlain Valley and northern slopes of the Adirondacks.
&&
.KEY MESSAGES...
As of 242 PM EDT Wednesday...
1. Strong gusty winds areawide are expected tomorrow as an
unseasonably strong area of low pressure track just north of the
area.
2. Scattered showers and thunderstorm today will taper off by
this evening, with more widespread rain and thunderstorms tomorrow.
Some storms tomorrow may become strong to severe with embedded heavy
rain and damaging winds.
3. Unsettled weather continues this weekend with some showers
and northwesterly breezes. A low pressure tracking offshore
Monday, may increase winds and rain chances further.
&&
.DISCUSSION...
As of 358 PM EDT Wednesday...
KEY MESSAGE 1: An unseasonably strong sub-985mb low will pass near to
north of Ottawa tomorrow with strong gusty winds expected. The
synoptic support is strong with a near 130 knot upper level jet
beginning to nose in overnight tonight, of which will be quite
elongated and nearly zonal. Convergent flow aloft will strengthen
the jet as it approaches, with a deep layer tightening pressure
gradient, leading to a vertically stacked low over eastern Ontario.
The synoptic setup is more reminiscent of something found in our
winter months, and is near record levels for overall surface
pressure for this time of year. As the pressure gradient tightens
and the system deepens, a low level jet at 850mb will also deepen to
nearly 100 knots aloft. Such a strong jet is also quite uncommon
appearing less than 1 day in 10 years for this time of year. These
strong winds in model soundings continue to denote even 40-50 knot
winds just off the surface at 500ft areawide. As a result a
widespread Wind Advisory has been issued for all of northern New
York and most of Vermont, outside of Orange and eastern Windsor
Counties from 8 AM tomorrow morning 8 PM tomorrow evening. Winds may
gust up to 45 to 55 MPH, in the Advisory areas, and perhaps up to 60
MPH near Malone, NY. The strongest winds will be focused in the
northern Champlain Valley as winds become channeled tomorrow morning
between 8 AM and 1 PM, as well as along the northern slopes of the
Adirondacks near the US-11 corridor due to downsloping of southerly
winds. Additional areas near the western facing slopes of the Green
Mountains of Addison, Chittenden, and Franklin Counties in Vermont
could also see further enhancement to 55 MPH gusts from downsloping
of southeasterly winds tomorrow morning. Winds will be below Wind
Advisory thresholds overall, but remaining gusty at times, in Orange
County and near the Connecticut River in general due to terrain
influences and weaker southeasterly winds near the surface. Impacts
from these winds will be downed tree limbs and isolated to scattered
power outages. Due to trees being fully leafed out, there may be
more tree damage than with similar wind speeds during the colder
months as the wind cannot as easily pass through the trees.
Winds will turn to the south and then southwest into tomorrow
afternoon, with a brief reduction below Wind Advisory thresholds for
an hour or two. However, as they become more southwesterly,
channeling in the St. Lawrence Valley will lead to a resurgence of
stronger winds, once again along the US-11 corridor. Winds may gust
again up to 55 MPH at times. Winds in Vermont tomorrow afternoon
will likely hover around Wind Advisory thresholds, but not be as
strong as in the morning, though some stronger gusts may still be
possible as mixing becomes stronger with some breaks in
precipitation. Winds will weaken back towards 25 to 35 MPH by
tomorrow night, though they will remain breezy from the west around
25 to 35 MPH through Friday and Saturday as an upper low remains
just north of the International Border and a jet streak at 250mb
lingers.
KEY MESSAGE 2: A strong sub-985mb low will bring widespread
precipitation tomorrow with chances for strong to severe
thunderstorms tomorrow afternoon. Isentropic lift associated with a
lifting warm front will allow widespread light to moderate rain to
increase from southwest to northeast by early tomorrow morning. Good
frontogenesis at 850 and 700mb will allow for a solid swath of
rainfall within a 4-8 hour window around sunrise tomorrow morning
where a majority of the rainfall for the system will fall. A strong
LLJ associated with the system will likely lead to some shadowing
across the Champlain valley and northern slopes of the Adirondacks
as rain becomes shredded by the strong winds. Furthermore,
southeasterly surface flow initially will lead to downsloping on the
western facing slopes of the Greens and Adirondacks which will
likely lead to pockets of reduced rainfall totals in the
aforementioned areas as well. As the warm front lifts late
tomorrow morning, and we get into a pseudo warm sector,
instability will begin to increase. However, soundings show a
stout warm layer aloft, with likely convective debris with mid
to high level clouds which will help to lower the equilibrium
level and reduce the realized total CAPE. However, with models
denoting some stronger mixing potential by tomorrow afternoon,
some wider CAPE profiles may be possible. In this low CAPE, high
Shear environment, some limitations and concerns will be
possible. If mixing becomes too strong, with increased surface
dry air, in tandem with the strong shear, dry air entrainment
will kill off any convective initiation, with more gusty shower
type activity. However, should mixing be just enough to sustain
wider CAPE, while mitigating dry air entrainment, the strong
shear profiles could lead to some embedded rotation. The Storm
Prediction Center has put areas along the Connecticut River in a
2% tornado risk for tomorrow. This is very conditional on the
instability levels, and if we can get a long enough break
between the morning warm frontal rain and thunderstorm activity
in the afternoon. Regardless, should any storms grow, regardless
of entrainment, gusty winds will be likely. It will not take
much to mix down the stronger LLJ winds within the shower or
thunderstorm activity. The best chances for any strong to severe
weather will be likely south of a line from Saranac Lake, NY to
Montpelier, VT. Any chances for severe weather will decreased
after 8 PM with some lingering light showers into the evening.
Shower chances continue into Friday and Saturday as an upper
trough lingers around the International Border.
Pwats will be around 1.5 inches by tomorrow morning, with around an
inch by the afternoon. Some locally good downpours will be possible
with the decent pwats, but flooding risks will be low with the quick
progression of the system as a whole. A few pockets of quarter to
half an inch per hour rates may be possible in the afternoon across
the Adirondacks and eastern Greens, as denoted on the latest 12Z
HREF run. Right now current thinking is that widespread quarter to
half an inch rainfall amounts are likely everywhere, with areas east
of the Greens and the Adirondacks potentially seeing up to an inch.
Areas that receive any thunderstorms, mainly in southern Vermont
could see between 1-2 inches. Anything above 2 inches looks unlikely
due to the lower confidence in stronger convective elements and the
quick progressive nature of the system.
KEY MESSAGE 3: Cyclonic flow remains aloft in the wake of The
Thursday system keeping conditions unsettled through Saturday
with breezy northwesterly winds likely. Gusts in excess of 20
mph are probable and will keep wave action high on Lake
Champlain. Terrain focused showers chances will continue with
upsloping along the Adirondacks and Greens. Temperatures will
trend noticeable cooler under sustained cold air advection, but
not remarkably colder due to eastern Canadian maritime source
region. Highs will decrease into the upper 60s and low 70s by
Saturday.
Monday, low pressure troughing will track move offshore and
develop into a closed system resulting in increased winds and
shower chances again. Current model consensus keeps the track
close enough to the shore to allow for deformation and
orographic precipitation to blossom across northern New York and
Vermont. However, a few models are splitting from consensus
suggesting that the track of the system isn`t a foregone
conclusion. These models are suggesting a flatter trajectory
that would result in a sharper moisture gradient across the
region that could preclude rain for portions of northern New
York and potentially northern Vermont. Temperatures are favored
to warm beyond Monday as ridging returns.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Through 18Z Thursday...VFR conditions will persist through 12Z
before CIGs lower as widespread showers spread over northern New
York and Vermont. 18-23Z showers and isolated thunderstorms are
favored with highest chances of TSRA over northern New York as
a trough swings through.
Largest threat to aviators 12-18Z Thursday will be strong SFC
gusts associated with a tight pressure gradient and LLWS ahead
of and along a front moving through the region. Can`t rule out
some strong convection either along the front, but will wait to
include in TAFs until they are closer. CIGs lower at least to
MVFR as gusts increase in excess of 30kts for most terminals.
Outlook...
Thursday Night: VFR. Slight chance SHRA.
Friday: VFR. Slight chance SHRA, Slight chance TSRA.
Friday Night: Mainly VFR, with local MVFR possible. Chance SHRA.
Saturday: Mainly VFR, with local MVFR possible. Likely SHRA,
Slight chance TSRA.
Saturday Night: Mainly VFR, with local IFR possible. Chance SHRA.
Sunday: Mainly VFR, with areas MVFR possible. Chance SHRA, Slight
chance TSRA.
Sunday Night: VFR. Slight chance SHRA.
Monday: Mainly VFR, with local IFR possible. Chance SHRA, Slight
chance TSRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Wind Advisory from 8 AM to 8 PM EDT Thursday for VTZ001>009-
011-016>020.
NY...Wind Advisory from 8 AM to 8 PM EDT Thursday for NYZ026>031-
034-035-087.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Danzig/Boyd
AVIATION...Boyd
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