808
FXUS61 KBTV 061133
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
733 AM EDT Sat Jun 6 2026
.WHAT HAS CHANGED...
As of 214 AM EDT Saturday...
The potential for a few strong to locally severe storms remains on
track from the previous forecast with chances for isolated embedded
gusty winds and small hail. Have slightly increased total rainfall
amounts through Sunday as well.
&&
.KEY MESSAGES...
As of 214 AM EDT Saturday...
1. A few strong to locally severe storms are possible this
afternoon and evening with isolated gusty winds, hail, and frequent
lighting as the primary threats.
2. Increasingly humid weather is expected beyond the latter
half of next week, with the potential for heat risk concerns.
&&
.DISCUSSION...
As of 214 AM EDT Saturday...
KEY MESSAGE 1: The potential for strong to locally severe storms today
remains on track with no major changes to the forecast. The Storm
Prediction Center has placed portions of southern Vermont, including
southern Rutland and southern Windsor Counties into a Slight Risk
(level 2 of 5) for potential severe weather this afternoon. Upper
level troughing centered over the Great Lakes this morning continues
to rotate eastward. Multiple embedded shortwaves on the latest RAP
analysis are evident, with the first of which beginning to enter the
St. Lawrence Valley. Associated shower chances are beginning to
spread east, though dry air from today and from the retreating ridge
are leading to mainly virga in this initial round of radar returns.
Strong moisture advection via a jet stream connection to the Gulf
with help saturate the column this morning into the early afternoon
as Pwats increase to 1.5 inches across the entire region. Given the
high precipitable water associated with this system, localized heavy
rain may be possible with any showers that do develop, though
torrential downpours are not favored due to a lack of true
convergence and strong shear, at least this morning. Into this
afternoon the rain will favor rounds of showers and embedded
thunderstorms which will be transient enough to keep our flood risk
low.
The initial shortwave shifts east by late this morning with some
clearing potentially in its wake via subsidence. This dry slot is
already evident on GOES-19 water vapor imagery across eastern
Michigan. Some peaks of sunshine will allow for an increase in
instability, mainly in the southern regions where distance from the
core of the trough will be greater. Surface instability is progged
to climb towards 1200-1800 J/kg on the NAM3 and HRRR model soundings
with slightly steepening lapse rates to 6.5 to 7C. The issue with
any convective initiation with the well saturated columns associated
with the high Pwats leading to likely a mess of convective debris
throughout the late morning to early afternoon hours. As the
boundary layer evolves in time with some efficient mixing from an
increasing LLJ around 20Z to scour out some low level moisture,
instability will increase across southern Vermont. Bulk 0-6km shear
is progged to increase at the same time to around 30-40 kts per
the latest HRRR soundings supporting some thunderstorm
activity. Furthermore, DCAPE in model soundings ranges from
650-850 J/kg which would support locally gusty winds, especially
when combined with the locally higher pwats. The main impacts
from these potential storms will be localized heavy rainfall,
frequent lighting, locally gusty winds, and some small hail.
Hail growth zone thickness to around 10,000 would support some
small hail formation. Timing of the stronger storms is likely
between 2 and 8 PM. Primary modes look to be isolated pulse
cells which may grow upscale with unidirectional shear into a
few mini bowing segments. The convective threat today should
end by 02-03Z with the loss of daytime instability and weakening
shear profiles.
A secondary shortwave on the back of the departing long wave trough
Saturday night into Sunday will bring another chance for showers and
embedded thunderstorms, mainly across southern Vermont. Northerly
flow will be advecting cooler air from the north with increasing waa
flow to the south leading to an area of enhanced convergence in the
Champlain Valley Saturday night. Models show a good reinforcement of
moisture along the northern Greens with potentially a few hours of
0.1 inch an hour rain rates with a quarter to a third of an inch
possible between midnight and daybreak Sunday. On Sunday, from
central Vermont to the southeast, additional shower activity will be
possible, though instability will be lower, only to around 500 J/kg
on model soundings for VSF. Continued chances for small hail will be
possible, though the chances of heavy rain will be less likely as
the jet streak slides south will a drying of the mid to upper
levels. Temperatures will trend cooler on Sunday with highs only in
the upper 60s to low 70s. As rain ends Sunday afternoon and
temperatures cool overnight, some patchy fog may be possible,
especially in the cold hollows of the higher terrain Sunday night.
KEY MESSAGE 2: The long range pattern will feature warm to hot weather
with increasingly muggy dewpoints. As surface high pressure off the
Eastern Seaboard ambles farther into the Atlantic, deep
southwesterly flow will increase. 925mb temperatures will be around
21-22 C, which usually corresponds with temperatures in the mid 80s
to around 90 F on Wednesday. Different forecast scenarios have come
into better alignment with a slow moving trough in a manner that`s
fairly consistent with our recent pattern. It shows a weakening
upper trough shifting in around Wednesday night, and then ridging
amplifying over top across Canada which shunts it southeastwards.
Within the warm, moist air mass, this will likely support greater
coverage of showers and thunderstorms on Thursday and Friday.
Following that, the high amplitude ridging that has persistently
developed from the Great Lakes into James Bay will settle more east
while a broad longwave trough becomes established across James Bay.
This will result in continued deeper southwesterly flow, meaning
warm-to-hot and muggier conditions will be here to stay. The
probabilities of Heat Indices climbing at or above 100 F are
beginning to rise across the Champlain Valley towards 30-40%. The
new probabilistic format of HeatRisk, which is specially formulated
to consider potential heat related illnesses indicates 50-70%
chances of reaching Major levels, which indicate the potential for
heat-health risks to anyone within our area.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Through 12Z Sunday...Light rain has been lifting northeast
across Vermont and northern New York. Despite most precipitation
being light with clouds generally above 7000 ft agl, there have
been some visibility reductions mainly 4-8 SM, but locally down
to 2-3 SM. This first wave of rain will shift east over the
next few hours while south to southwesterly flow begins to
accelerate with sustained winds around 7 to 12 knots and
intermittent gusts of 16 to 22 knots.
The precipitation outlook beyond 16z-17z is challenging.
There`s little agreement on convective initiation and how much
activity we will receive. Thus, the forecast still uses mostly
PROB30s to indicate chances for thunderstorms between about
18z-01z. Expect changeable weather. A sharper trough will begin
to approach 21z-02z, and this will begin turning winds
southwest to west with a slight increase in wind speeds and
gusts. Behind the trough, additional showers are expected with
lowering ceilings, likely 800-2500 ft agl beyond 04z. Pockets of
LLWS are also expected with northwest winds of 35-40 knots at
2000 ft agl. This will move east about 08z, but additional rain
will move north to south from the international border following
this.
Outlook...
Sunday: Mainly MVFR, with local IFR possible. Chance SHRA.
Sunday Night: VFR. Patchy BR.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. Chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Haynes/Danzig
AVIATION...Haynes
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