674
FXUS61 KBTV 171106
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
706 AM EDT Wed Jun 17 2026
.WHAT HAS CHANGED...
As of 226 AM EDT Wednesday...
Confidence has increased for strong to severe thunderstorms on
Thursday afternoon.
&&
.KEY MESSAGES...
As of 226 AM EDT Wednesday...
1. A pair of systems expected to track through today and
tomorrow. The second on Thursday will bring more potential impacts
of winds and thunderstorms with embedded heavy rain and damaging
winds.
2. Showery, breezy conditions are expected for the early
portion of the weekend.
3. A low pressure system will likely bring widespread rain to
the region on Monday, followed by seasonably warm temperatures next
week.
&&
.DISCUSSION...
As of 226 AM EDT Wednesday...
KEY MESSAGE 1: Today will open up with increasing clouds and some
showers and thunderstorms as an upper trough lifts northeast.
Although it`s not the strongest trough, it`s managed nighttime
convection in the Great Lakes region. South flow today should allow
for moderation into the 70s to near 80 today. Despite somewhat dry
dewpoints, good lapse rates in tandem with the upper trough should
produce scattered to numerous shower activity. Winds aloft are not
strong, but with dry air entrainment, there should be some
acceleration of winds in any thunderstorms. Looking upstream at
Buffalo, NY, showers and storms have produced gusts around 30-35
knots. So that could be in the cards for us too.
Thursday`s activity will be more significant. A sub-990mb low will
pass near to north of Ottawa. The level of synoptic support is quite
strong with a near 130 knot upper level jet nosing in.
Isentropic ascent, some elevated instability, and large scale
lift will result in a swath of moderate to heavy rain as the
warm front races northeast. After the warm front lifts out of
the region, the question continues to be how much wind will be
able to mix to the surface after any rainfall. Winds of 45-50
knots descends to about 1500-2000 ft above ground levels. So it
will not take much to mix winds to the surface; however, the
warm sector has trended towards continued convection embedded
within the warm sector as occlusion quickly takes place late
Thursday morning into the afternoon. For now, max wind gusts are
depicted reaching 30-40 mph, and locally up to 45 mph near
Malone, New York. With all the leaves on the trees, this could
pose a greater likelihood for downed branches. Isolated to
scattered power outages will be possible on Thursday.
Next on Thursday will be the convection: The Storm Prediction Center
has upgraded the Severe Weather Outlook to a Slight Risk (Level 2 of
5) for isolated strong to severe thunderstorms. The situation
involves high shear in the 0-6km layer of 45-55 knots while
instability of 500-750 J/kg and somewhat low equilibrium levels make
it likely that activity remains short and tilted. CAMs are split on
timing as well, and that will affect how much instability convection
has to develop. With the fast flow, the main concern will be whether
any storms can mix down the strong winds to the surface, and that
will be the primary severe weather hazard. Given such a strong
surface low, excellent inflow from southeast flow, and the quick
westerlies aloft, rotating updrafts are possible. The HREF/REFS
indicates some helicity tracks through the region as well. However,
the strong shear mentioned before may tilt updrafts too much to
sustain organized convection. The system will track east Thursday
evening with storms clearing the region.
KEY MESSAGE 2: Thursday`s strong low pressure gets stuck near Quebec
City for a few days with an upper low nearby. This will impart
breezy west-northwest winds with occasional showers. The greatest
chances will be along the international border given proximity to
the surface low. Both days feature some tall, skinny CAPE profiles.
Given that fast flow will continue with some good low-level lapse
rates, a few showers could produce gusty winds, but none are
anticipated to be particularly strong. Temperatures will trend
cooler heading into the weekend with a seasonable day Friday before
the core of the coldest air arrives Saturday placing temperatures in
the lower 60s to lower 70s.
KEY MESSAGE 3: A deep trough over the Canadian maritimes will linger
through the weekend bringing showers and the occasional thunderstorm
to the Northeast before finally shifting out into the Atlantic Ocean
early next week. There remains the potential for a potent low
pressure system to pass to our south which would produce widespread
rain and embedded thunderstorms across the region on Monday and
Monday night. Deterministic models continue to disagree on
exact track and timing of this system, with 40-65% chance of
measurable precipitation Monday afternoon and 25-50% chance of a
half an inch within 24 hours during this period. With so much
disagreement in the deterministic global models, temperatures
early next week may depend on precipitation, but the majority of
models at this point seem to be suggesting temperatures could
increase to and even reach slightly above seasonal normals by
midweek with highs in the upper 60s to lower 80s and lows in the
upper 40s to lower 60s.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Through 12Z Thursday...VFR conditions are expected to be the
main flight category over the next 24 hours. Winds will become
south to southeast with speeds 6-11 knots, and perhaps a few
gusts 16-18 knots. Showers will begin to develop in association
with an incoming trough as early as 15z, but a few thunderstorms
will likely develop later in the afternoon. The most likely
areas for thunder will be SLK, PBG, and MSS from about 16Z
through 23Z Wednesday. Showers will steadily wane after 23z.
About 06-10z, a strong warm front will begin to lift northeast.
Along and behind it, a near solid swath of rain is expected,
followed by increasing winds and some LLWS. For now, since most
impacts will begin approaching and then after 12z, they aren`t
explicitly mentioned at this time.
Outlook...
Thursday: Mainly VFR, with areas MVFR possible. Windy with gusts
to 30 kt. Definite SHRA, Slight chance TSRA.
Thursday Night: VFR. Windy with gusts to 30 kt. Chance SHRA.
Friday: VFR. Chance SHRA, Slight chance TSRA.
Friday Night: VFR. Chance SHRA, Slight chance TSRA.
Saturday: Mainly MVFR, with local IFR possible. Likely SHRA,
Chance TSRA.
Saturday Night: MVFR/IFR conditions possible. Chance SHRA.
Sunday: Mainly VFR, with local MVFR possible. Chance SHRA, Slight
chance TSRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Haynes
DISCUSSION...Storm/Haynes
AVIATION...Haynes/Storm
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