791
FXUS61 KBTV 162347
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
747 PM EDT Sat May 16 2026
.WHAT HAS CHANGED...
As of 734 PM EDT Saturday...
The threat of any thunder has dropped, with little to no
lightning being observed with showers this evening. The latest
SPC mesoanalysis shows very little instability and don`t expect
this to change, so have updated to remove the slight chance of
thunder from the forecast.
&&
.KEY MESSAGES...
As of 242 PM EDT Saturday...
1. Warm weather is expected to continue this weekend, with a
few isolated to scattered showers possible later this afternoon into
the evening.
2. Heat increases further during the first half of next week
with highs in the mid 70s to 80s each afternoon. Remember to
stay safe in warmer temperatures by staying hydrated and taking
frequent breaks if working outside.
3. Thunderstorm chances increase late Tuesday through Wednesday
as a front moves through the region.
4. Cooler and dry to end the week.
&&
.DISCUSSION...
As of 242 PM EDT Saturday...
KEY MESSAGE 1: Surface low pressure is tracking across Lake Superior
this afternoon while a preceding upper shortwave approaches northern
New York and Vermont from Lake Huron. This shortwave will bring some
showers to the forecast area later this afternoon and evening,
likely beginning across the St. Lawrence Valley around 4PM - 7PM and
progressing eastward. While elevated instability is non-zero, we`re
not expecting much thunder or even very much measurable rain from
these showers. Best instability occurs around 6 PM into the evening,
when a rumble of thunder is possible. The showers should largely be
short-lived and light, bringing a few hundredths of an inch of
precipitation to the region. Along with these showers, a low level
jet is expected to arrive this evening. Already we`re seeing
afternoon mixing bring wind gusts to around 20 mph in spots. We
anticipate this should continue and increase along the low level jet
this evening, with highest gusts in channeled areas like the St.
Lawrence and Champlain valleys. Under the jet, gusts are expected to
get as high as 25-35 mph in these areas. Temperatures currently in
the 70s for most will fall back down to the upper 40s and 50s
overnight tonight, well above seasonal averages for mid to late May
as the shortwave and showers keep conditions relatively cloudy at
night. Probability of measurable precipitation overnight is around
25-65%. Sunday will be a dry day with high pressure building in from
James Bay in Canada and upper level ridging beginning to build over
the region. A light west-northwesterly breeze will keep temperatures
from getting too high, but skies will be on the sunny side and
temperatures are anticipated to climb into the 70s and lower 80s.
Despite the warm air temperatures, water temperatures are still
quite cold, so please use extreme caution if recreating on bodies of
water this weekend.
KEY MESSAGE 2: Upper level ridging will crest over the region on Monday
as a warm front cross the forecast area at the surface, ushering the
region into southerly flow. Temperatures at the 925 mb level are
modeled around 20-25 C by Monday afternoon, resulting in highs at
the surface in the mid 70s to lower 80s F. These temperatures will
be the warmest of the year so far. It is important to remember to
stay safe in warmer temperatures by staying hydrated and take
frequent breaks if working outside, especially after we had such a
cool start to the month. Some folks may not be prepared for the
quick warmup with many window AC units not yet installed for the
summer. Tuesday, we`ll be solidly in the warm sector, with 925 mb
temps 23-26 C and surface highs reaching widespread 80s. One
limiting factor in reaching surface temps in the 80s could be
showers and embedded thunderstorms plus associated clouds, mainly in
the afternoon. More on that in Key Message 3.
KEY MESSAGE 3: As heat and humidity build Tuesday, instability
will also build. A frontal boundary, ridge-riding vort maxes,
and low level jet will cross the forecast area Tuesday afternoon
into a warm, moist air mass with modest instability, 500-1000
J/kg, to work with. Dew points will likely range in the upper
50s and 60s ahead of the front. Showers with embedded
thunderstorms are likely Tuesday afternoon, about 40-80% PoPs
across portions of northern and central Vermont. Tuesday night
into Wednesday, models continue to show a frontal passage that
will likely be a focal point for convection as it tracks through
the region. Timing of the front is currently during the day
hours suggesting added instability associated with heating is
probable. This pattern shows some potential for a few stronger
variety storms with highs in the 70s to mid 80s Wednesday, but
changes in frontal timing could limit or move the window of
concern.
KEY MESSAGE 4: Surface high pressure builds out of Canada for the end
of the week, bringing mostly dry conditions and cooler temperatures.
Highs generally look to be in the 60s and lows look to be in the
40s. With surface high pressure potentially centering overhead,
there is the potential for efficient radiational cooling and frost
freeze concerns in the colder spots, but whether temperatures will
be able to drop far enough remains uncertain.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Through 00Z Monday...Light rain showers associated with a weak
surface front will cross the region early in the TAF period, and
should exit into NH by midnight. Brief periods of MVFR ceilings
will be possible in showers, mainly at KMSS/KSLK/KEFK, but
anticipate VFR conditions to prevail at most terminals
overnight. The exception will be at KSLK and perhaps KMSS; skies
will clear late this evening as drier air moves in behind the
front, but hi-res guidance indicates low-level moisture will
become trapped under the building subsidence inversion,
particularly down wind of Lake Ontario. Hence ceilings of
1200-2500 ft are expected at KSLK from 03z until 13z Sunday.
There are some indications that clouds could drop below 1000 ft,
but confidence in this extending all the way eastward to KSLK
is low, with the best chances remaining across southern St
Lawrence County back toward Lake Ontario. Regardless, low clouds
will erode with daytime heating on Sunday, with VFR to prevail
at all terminals from 13z onward with FEW-SCT clouds AOA 3500
ft. South/southwest winds will trend more toward the west behind
the front, with gusts of 15 to 25 kt expected through the
evening, particularly at KMSS. Winds will eventually become NW
6-12 kt overnight into early Sunday morning, gusting to around
20 kt after 14z.
Outlook...
Sunday Night: VFR. NO SIG WX.
Monday: VFR. NO SIG WX.
Monday Night: VFR. Slight chance SHRA.
Tuesday: VFR. Chance SHRA, Chance TSRA.
Tuesday Night: VFR. Chance SHRA, Slight chance TSRA.
Wednesday: Mainly VFR, with areas MVFR possible. Likely SHRA,
Slight chance TSRA.
Wednesday Night: VFR. Slight chance SHRA.
Thursday: VFR. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Hastings
DISCUSSION...Storm/Myskowski
AVIATION...Hastings
|
