049
FXUS61 KBTV 212331
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
731 PM EDT Thu May 21 2026
.WHAT HAS CHANGED...
As of 147 PM EDT Thursday...
The Freezing Warning has been expanded across the rest of the
Northeast Kingdom and portions of north-central Vermont.
&&
.KEY MESSAGES...
As of 147 PM EDT Thursday...
1. Widespread frost and freeze expected tonight, with Saranac
Lake and Montpelier`s climate sites within reach of record lows, and
then temperatures will gradually moderate through the remainder of
the week.
2. Rain expected Saturday night into Sunday.
3. Somewhat unsettled for Memorial Day and into the middle of
the work week, with seasonable temperatures expected. Drying trend
in the long term looking likely.
&&
.DISCUSSION...
As of 147 PM EDT Thursday...
KEY MESSAGE 1: Cool, dry weather is present over the region as a strong
surface high slides across the northern latitudes. It`ll be directly
overhead tonight. Although there are some high clouds present, it
appears likely to thin out, and they may not have too much of an
impact on radiational cooling. The latest MET guidance has 22 for
SLK and 29 for MPV. If we meet or exceed this, we could experience
daily record lows. Blended guidance like the NBM can really struggle
on these kind of nights and generously utilized MOS and high res
guidance capable of capturing some of the cool drainage in drainage
basins. Freeze warnings have been expanded in central Vermont given
proximity to the freezing point. For now, the only hard freeze
potential seems to be localized to some of the coldest locations,
like the perennial cold possible at the Adirondack Airport/SLK. The
only area without any frost headlines remains the northern Champlain
Valley, which appears to hover near or over 36F . There could
be some frost within some of the colder pockets within the
northern Champlain Valley. NBM probabilities less than 36 F
suggest a 15% chance or less away from Lake Champlain and a 5%
chance near Lake Champlain, but if you don`t want to even risk
the low end possibility, then it never hurts to cover or bring
in tender plants.
Friday will observe some moderation, and then with the slowing of
precipitation and clouds Saturday evening into Sunday, we will have
the potential for another cold night on Friday into Saturday, but
with mid 30s to mid 40s allowing only localized frost. Then
temperatures will climb towards seasonal norms with mid 60s to lower
70s on Saturday afternoon. Dry weather is expected with nil PoPs and
low RHs. Today will be the windiest day before high pressure allows
for only light winds.
KEY MESSAGE 2: Surface high pressure off the Canadian maritimes will be
around 1035mb, which is quite strong for this point of the year.
Forecast soundings show such dry air in place that precipitation
will really struggle to lift northeast. Some have 850-500mb
dewpoints at or below -20 C across that entire layer. We may see
returns on the radar in the mid to upper levels, but it will all be
virga. Increasingly confluent flow and an increasingly strong LLJ
will begin to increase moisture fluxes and mix out the dry air in
place. The degree to which we see rainfall across the region varies
between a trace or a few hundredth up to a half inch. The brief tap
of moisture is rather thin, and it will be relatively progressive.
So the alignment of favorable moisture with dynamical support may be
relatively short-lived. Ensemble guidance is at least somewhat
optimistic, and despite the NAM12`s impressive 70kt 850mb jet, it
shows little terrain shadowing. There will be some orographic
influence to rainfall, but it may not be everything given the
efficiency of moisture transport and forcing. There are some timing
differences that remain amongst various model scenarios as well. A
cool, cloudy, and breezy Sunday with a 3-9 hour block of stratiform
rainfall is expected. The general consensus for amounts is about a
tenth to a third inch.
KEY MESSAGE 3: High pressure will attempt to nudge into the region from
the west to start off next week, but a lingering coastal system over
southern New England could keep some chance of rain for Memorial
Day. While not a washout by any means, trends have moved towards not
a fully dry Memorial Day with some wrap around moisture. Likely,
there will be some isolated to scattered showers across the region,
primarily in the morning, becoming more confined to the higher
terrain into the afternoon on Memorial Day. Showers do look to be
relatively weak given lower PWATs and decent flow aloft with 50
knots at 500mb. Drier air does look to take hold for Monday night
through most of Tuesday. Temperatures for the early to mid week next
week will be seasonable with highs in the 70s and overnight lows in
the 40s. Shower chances return late Tuesday into Wednesday as an
upper shortwave over eastern Quebec swings into the Canadian
Maritimes with a trailing cold front over our region. As the system
drops south, ensemble guidance is somewhat depicting a weak coastal
low which may keep some moisture and shower chances into Wednesday
night and perhaps Thursday morning. Regardless, as shower chances
drop off by late next week, prolonged drier air is forecasted
through much of the remainder of May in the long term.
Broad strong high pressure is expected to build in over the Great
Lakes with ridging across the Mid-Atlantic and Northeast bringing
more dry air and rising temperatures.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Through 00Z Saturday...High pressure building into the region
will provide all 7 of our taf sites with VFR conditions for the
next 24 hours. North to northeast winds 5 to 10 knots this
evening will become light 2 to 6 knots overnight into Friday. A
few-scattered high clouds are possible from time to time.
Outlook...
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. Chance SHRA.
Sunday: Mainly VFR, with local MVFR possible. Likely SHRA.
Sunday Night: MVFR/IFR conditions possible. Chance SHRA.
Memorial Day: Mainly MVFR, with areas IFR possible. Chance SHRA.
Monday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Tuesday: VFR. Slight chance SHRA, Slight chance TSRA.
&&
.CLIMATE...
Montpelier, VT (KMPV) and Saranac Lake, NY (KSLK) are expected
to fall within 3 degrees of their record low. Below are the
daily record values under threat for May 22nd, and the present
forecast.
Record | Year | Forecast Temperature
KMPV: 29 | 2002 | 31
KSLK: 22 | 1935 | 24
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Frost Advisory from 11 PM this evening to 8 AM EDT Friday for
VTZ009-011-016>021.
Freeze Warning from 11 PM this evening to 8 AM EDT Friday for
VTZ003-004-006>008-010.
NY...Frost Advisory from 11 PM this evening to 8 AM EDT Friday for
NYZ026-027-087.
Freeze Warning from 11 PM this evening to 8 AM EDT Friday for
NYZ029>031-034.
&&
$$
WHAT HAS CHANGED...Haynes
DISCUSSION...Haynes/Danzig
AVIATION...Taber
CLIMATE...Haynes
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