367
FXUS61 KBTV 210625
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
225 AM EDT Thu May 21 2026

.WHAT HAS CHANGED...
As of 152 AM EDT Thursday...

Frost Advisories and Freeze Warnings were issued for Thursday
night/Friday morning.

&&

.KEY MESSAGES...
As of 152 AM EDT Thursday...

1. Strong high pressure will support a widespread frost and
freeze tonight. Localized hard freeze conditions are possible.

2. Chances for rain increases on Sunday as a warm front pushes
into the area.

3. Somewhat unsettled for Memorial Day and into the work week,
with seasonable temperatures expected.

&&

.DISCUSSION...
As of 152 AM EDT Thursday...

KEY MESSAGE 1: Focus for the late week period will be on temperatures,
especially potential for sub-freezing lows tonight. In a pattern
like this where we expect mainly clear skies, calm winds, and an
anomalous dry air mass (characterized by precipitable water near the
5th percentile), Model Output Statistics tend to be fairly skillful
compared to the National Blend of Models and we have heavily leaned
the forecast towards this data. While there is some possibility of
mid-level clouds currently over the Midwest leaking out into our
region, most model guidance shows clear skies. As such, confidence
is fairly high that we should achieve some of the lowest
temperatures possible with this air mass. Therefore, we have issued
freeze warnings for the Adirondacks and far northeastern Vermont
where coverage of sub-freezing temperatures will be widespread. Many
locations within the northern Adirondacks could also see
temperatures drop below 28 degrees, resulting in a hard freeze.
Coverage of freeze conditions elsewhere in north central/
northeastern Vermont is somewhat patchy that warnings were not
issued, but potential for expansion exists. For example, the latest
MET MOS guidance at the Montpelier Airport in Berlin is 27 degrees
for a low temperature but 33 from the MAV MOS. Similarly, while most
of the Champlain Valley does not have a Frost Advisory at this time
due to limited coverage, frost is expected anywhere temperatures
drop into the mid 30s. As such, advisories could be issued if
forecaster confidence in temperatures falling into this range
overnight increases closer to Lake Champlain.

Low temperatures Friday night also trended lower along with a
decrease in sky cover, given preference for much of the
deterministic guidance showing skies remaining mainly clear again as
a sprawling high pressure area remains overhead. The low level
temperatures will have increased substantially (850 millibar
temperatures near 0 Celsius on Thursday night are progged to be near
5 Celsius Friday night), which will limit coverage of frost quite a
bit with lows mainly in the upper 30s to mid 40s. Frost looks
primarily in the northwestern Adirondacks and eastern Essex County,
Vermont. However, the large scale pattern favors northeastern
Vermont seeing localized frost conditions, where low temperature
forecasts are only slightly above the needed threshold.

KEY MESSAGE 2: Model guidance supports higher chances for rain
areawide on Sunday, with even the driest ensemble scenario
showing at least likely rainfall at some point during the day.
It appears a relatively organized wave of weak low pressure will
accompany a warm front such that forcing for precipitation
overcomes the strong upper level ridging out ahead of the
system. Expect stratiform, soaking rain spreads northeastward
during the morning hours with some lingering rain in the
afternoon before the frontogenesis exits. The intensity of the
rain is rather questionable, although hydrologically speaking
rainfall still looks light. However, amounts still are uncertain
in particular given precipitation distributions skewed by some
unlikely, very wet scenarios. Realistic driest scenarios lead
to totals as little as a trace to a few hundreths of an inch of
rain, most likely in northeastern Vermont. As of now, the
consensus idea shows about a quarter inch of rain is possible in
the Champlain Valley and central Vermont, and a third to half
inch of rain in southern portions of Vermont into much of
northern New York.

KEY MESSAGE 3: High pressure attempts to build in from the west while
the upper trough swings across the region on Memorial Day. There`s
considerable spread in both deterministic and ensemble solutions in
how quickly rain exits to our east and make way for the drier
airmass associated with the incoming high. It`s roughly split
between a mostly dry Memorial Day and a wetter one, especially
during the morning hours. Current thinking is perhaps the NBM/WPC
forecast is a bit overdone, but given the uncertainty, have stayed
with their PoPs/wx for now. Drier weather does seem to take hold by
Monday night, but then shower chances increase again later Tuesday
into Tuesday night as an upper shortwave trough swings around low
pressure centered near the Gaspe Peninsula/Canadian Maritimes.
It`s after this system moves by that we could get into stronger
ridging, with temperatures rising back above normal toward late
week.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
Through 06Z Friday...Brisk northwest winds 5 to 15 knots with
localized gusts up to 20 knots will cause areas of turbulence
near trrn this evening, before slowly weakening. Otherwise, VFR
conditions are expected to prevail for the next 12 to 24 hours
at all 7 of our TAF sites. A few gusts 15 to 20 knots are
possible again on Thursday between 15-21z.

Outlook...

Friday: VFR. NO SIG WX.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. Chance SHRA.
Sunday: Mainly VFR, with local MVFR possible. Chance SHRA.
Sunday Night: Mainly MVFR, with local VFR possible. Chance SHRA.
Memorial Day: MVFR. Chance SHRA.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Frost Advisory from 11 PM this evening to 8 AM EDT Friday for
     VTZ003-006>011-016>021.
     Freeze Warning from 11 PM this evening to 8 AM EDT Friday for
     VTZ004.
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...Kutikoff
DISCUSSION...Hastings/Kutikoff
AVIATION...Hastings