677
FXUS61 KBTV 161844
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
244 PM EDT Tue Jun 16 2026
.WHAT HAS CHANGED...
As of 240 PM EDT Tuesday...
Downslope gusty wind probabilities up to 45 MPH on the western
facing slopes of the central and northern Greens mountains, as
well as the northwestern Adirondacks have increased. Have
subsequently increased winds in the aforementioned areas.
&&
.KEY MESSAGES...
As of 240 PM EDT Tuesday...
1. Isolated to scattered showers with a few thunderstorms
possible this afternoon, and more likely Wednesday afternoon.
2. Widespread rain with embedded thunderstorms, with the
potential for gusty winds, are expected Thursday as a strong area of
low pressure passes to our northwest.
3. Cool and showery weather is expected over the weekend.
Before temperatures return to seasonably warm next week, a low
pressure system may bring widespread rain on Monday.
&&
.DISCUSSION...
As of 240 PM EDT Tuesday...
KEY MESSAGE 1: Weak shortwaves out ahead of a more developed long wave
trough will move from the southwest to the northeast this afternoon
and tomorrow afternoon. Weaker forcing is expected today, but an
isolated shower with a thunderstorm may be possible across the
Adirondacks. Due to increasing clouds and some drier air, fog
potential will be low tonight. Though chances will slightly increase
if an area receives rain today and is in a sheltered location.
Tomorrow, another shortwave with better forcing will move
northeastward through northern New York into Vermont. Terrain driven
showers will likely develop in the Adirondacks and then across the
Greens with cooling air aloft and some weak surface based
instability. Equilibrium levels will be quite low below -10C, which
will keep most convection shallow. However, a few thunderstorms may
be possible, with the best chances closer to the International
Border and northern St. Lawrence Valley where longer daytime heating
will be with better, albeit still weak, shear profiles will be
located. Most showers or thunderstorms tomorrow will be more garden-
variety with no significant weather expected. Highs tomorrow will be
a few degrees warmer than today with winds turning to the south
helping to increase some moisture. But we will lack the deep layer
moisture needed for any moderate to heavy rain.
KEY MESSAGE 2: An unusually strong area of low pressure will track
across eastern Ontario and pass just to our northwest on Thursday.
Ensemble models depict this system to have a pressure between 980-
985mb, which is in the 0.1 percentile, or near record levels for
overall surface pressure this time of year. This type of surface
pressure would be more reminiscent of something found in our winter
months. A precipitation shield associated with a warm front will
begin to lift through the region early Thursday morning with strong
ascent associated with waa and developing frontogenesis along the
warm front at both 850 and 700mb. A solid swath of rainfall is
expected within a 4-8 hour window around sunrise Thursday morning
where the majority of the rainfall for the system will fall. Trends
for the center of the system have jogged the center a bit north,
which could cut down on the overall rainfall amounts. Furthermore,
given the strong nature of the system, a strong LLJ around 70kts
will likely lead to some shadowing in the central Champlain Valley
with further rainfall reductions. As the warm front lifts, 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 and mid to high level clouds which will help to
lower the equilibrium level and reduce the realized total CAPE.
Regardless, some daytime heating may allow for a some thunderstorms
to develop around noon and persist into the afternoon. Confidence in
any severe weather is relatively low with a low CAPE, high shear
type profile expected, but a few storms may become strong, mainly in
southern Vermont. Pwats will be around 1.5 inches by the afternoon
which could lead to some locally good downpours, but flooding risks
will be low with the quick progression of the system as a whole.
Right now current thinking is that widespread quarter to half an
inch rainfall amounts are likely everywhere, with areas in the
Northeast Kingdom and St. Lawrence Valley 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 strong convective elements
and the quick progressive nature of the system.
The more concerning aspect to this system will be the potential for
strong gusty winds during the day Thursday. As mentioned, there will
be a strong LLJ to 70 knots around 4-5 kft moving into the region as
the warm front lifts north Thursday morning. HRRR and NAM3 Model
soundings denote the possibility of 40 knot winds at 900 ft in
Cambridge, VT. Winds at the surface will be southeast to east
Thursday morning towards noon, and with some cold air damming across
the eastern Greens, and strong flow aloft, downsloping on the
western facing slopes of the central and northern Greens is becoming
increasingly likely. We have increased the forecast gusts to around
45 MPH for locations like Cambridge, Montgomery Center, and
Middlebury (including other towns on the western facing slopes of
the Greens) on Thursday. Channeled flow in the Champlain Valley will
also lead to the potential for gusty winds around 40 MPH through
Thursday late morning. We will continue to monitor the potential for
any wind product issuances should trends continue. Winds will turn
southwesterly by Thursday afternoon, weakening the downsloping winds
in Vermont, but subsequently increasing or sustaining 30 to 40 MPH
gusts across the St. Lawrence Valley. Winds do not totally calm
Thursday night, as a pressure gradient will remain across the
International Border, keeping winds relatively breezy into Friday.
Northwest flow and cooling temperatures aloft will keep Friday
relatively breezy with some chances for precipitation, mainly near
the International Border.
KEY MESSAGE 3: As we move into the beginning of the astronomical
summer, the weather pattern will be one more typical of winter with
a deep trough over the northeastern US lingering through the weekend
before finally retreating. There is increasing confidence in well
below normal temperatures, particularly on Saturday when cool, west-
northwesterly cyclonic flow will be present. The latest temperature
guidance shows highs will certainly be cooler than normal and likely
at least 5 to 10 degrees below normal; relatively large spread
suggests forecast highs could further trend lower in the next couple
of days, especially if the colder air aloft. There are subtle
differences in the placement of the trough and shortwaves that
traverse it from the northwest that lead to differing chances of
rain showers, but the blend of this guidance seems reasonable at
this time with numerous showers expected to pinwheel in from the
north and west.
The takeaway would be that rain showers from Saturday into Saturday
evening are likely to near certain, with chances peaking during the
afternoon hours, but precipitation rates/amounts will not cause any
impacts with very shallow instability expected. One camp of
guidance, dominated by the ECMWF ensemble, is more amplified with
the upstream heights and brings us more instability than the
consensus forecast, such that a rumble of thunder can`t be ruled out
at this point. Shower chances will be substantially lower on Sunday
as the trough and associated upper level low scoots well to our
northeast, but lingering cyclonic flow will be present to support at
least scattered afternoon showers, and perhaps a thunderstorm or two
will develop as temperatures trend a bit more seasonable.
With regards to early next week, some deterministic guidance
continues to show the potential for a potent low pressure system to
pass to our south which would bring widespread rain and cool
conditions to the North Country on Monday/Monday night. At this
time, it is too early to know if the storm will come together and/or
track northeastward to bring any substantial rain to our region.
There are mixed signals across the ensembles right now to the point
that a general chance of rain, increasing in likelihood Monday
afternoon and decreasing Monday night, looks reasonable at this
time. The threat of heavy rain is low but bears watching (the
wettest solution, in 8% of the most recent full ensemble, does show
24 hour rainfall in the 1 to 2" range).
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Through 18Z Wednesday...VFR conditions are expected along with
mainly light winds. A spot shower is possible during peak
heating this afternoon as a few cumulus grow overshooting tops
in the western Adirondacks and a PROB30 was used at SLK from 19Z
to 21Z given risk of convection; otherwise there will be no
precipitation in the airspace today and tonight. While there is
no mention of showers after 12Z, will note towards the end of
the TAF period a few showers could develop with more coverage
anticipated after 18Z. Winds generally look 10 knots or less
with only modest southerly flow for much of the period.
Outlook...
Wednesday Night: VFR. Chance SHRA.
Thursday: MVFR/IFR conditions possible. Definite SHRA, Slight
chance TSRA.
Thursday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Friday: VFR. Chance SHRA, Slight chance TSRA.
Friday Night: Mainly VFR, with areas MVFR possible. Chance SHRA,
Slight chance TSRA.
Saturday: Mainly VFR, with areas MVFR possible. Likely SHRA,
Slight chance TSRA.
Saturday Night: Mainly MVFR, with areas IFR possible. Chance
SHRA.
Sunday: MVFR/IFR conditions possible. Chance SHRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Danzig
DISCUSSION...Danzig/Kutikoff
AVIATION...Kutikoff
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