699
FXUS61 KBTV 211818
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
218 PM EDT Mon Sep 21 2026

.WHAT HAS CHANGED...
As of 217 PM EDT Monday...

No changes to the current forecast.

&&

.KEY MESSAGES...
As of 217 PM EDT Monday...

1. Tranquil weather conditions expected through late week, with
patchy frost possible nightly through Wednesday night.

2. Little change in latest forecast with mostly dry conditions
prevailing into the upcoming weekend with near normal temperatures.

&&

.DISCUSSION...
As of 217 PM EDT Monday...

KEY MESSAGE 1: Fair, cool, and calm weather will settle in across the
region tonight through the the late week. Low-level stratocumulus
clouds will linger this afternoon, and eventually become more
scattered this evening as strong high pressure begins to take hold
from the north. This high will keep any moisture and precipitation
chances shunted well south of the area. A seasonably cool and dry
air mass will shift south tonight with just a few mid-high clouds.
Fog and frost potential looks fairly low tonight, outside of some of
the more sheltered valleys of the Adirondacks and central Vermont
due to cloud cover and some subtle flow around 1000ft agl. Cool
northerly advected air will keep highs tomorrow in the low to mid
60s, and the higher terrain in the 50s; summit levels around the low
to mid 40s. Skies will gradually clear from the west throughout the
day tomorrow with some clouds lingering in southern Vermont,
associated with a stationary boundary well south of the region. The
better frost/fog potential this week will be Tuesday night.
Temperatures have the chance to dip below 40 for the first time this
season even in the Champlain Valley. Widespread near freezing
temperatures will be possible across the Northeast Kingdom, central
Vermont, and the Adirondacks. Pocket mid to upper 20s will be
possible with a hard freeze likely in isolated portions of the
northern Adirondacks. Frost Advisories will likely be needed
tomorrow night for most of the central and northern Vermont, in
addition to portions of the northern St. Lawrence Valley. It should
be noted that, as of today, these products will no longer be issued
for the Adirondacks and Northeast Kingdom, as median date of the
first autumn freeze has passed. Thus, the growing season is
considered ended in these areas.

Through mid to late week, temperatures will slowly creep up a degree
or two each day towards Thursday, with highs in the mid to upper
60s, as the high drifts to the east. Portions of the eastern Greens
may see below normal temperatures continue Wednesday with a cold air
damming setup. Frost potential will continue Wednesday night, though
radiational cooling will be a touch weaker. Fog potential will also
be low or non-existent due to a detachment from rainfall by the end
of the week.

KEY MESSAGE 2: The primary challenge for the extended forecast is
potential for rain showers to impact eastern/southern sections this
weekend. Little change has been observed in the 12z guidance, with a
large spread in potential solutions associated with potential
coastal system. 12z GFS ensemble data shows 0.10 to 0.30" of qpf
acrs our central/eastern and southern cwa, while near the
International Border stays dry. Latest 12z GFS shows best
moisture/lift sliding to our south with mid/upper lvl closed system
capturing sfc low pres well off the SNE coast. However, several GFS
ensemble members and latest 12z ICON/CMC would have a little precip
advecting back into our region. Either way impacts look minimal
attm. Initially given very deep dry layer in place with pw values
only in the 0.20 to 0.40" range, expect large daily swings in temps
with cool nights and mild days. Highs generally in the 60s to near
70 late week into the upcoming weekend with lows upper 20s to lower
40s. However, if more clouds/precip develops this weekend than
expected highs will be 4 to 8 degrees cooler, especially associated
with north/northeast flow. The prolonged duration of very minimal
rainfall could result in expansion of drought conditions across
portions of our region as we head into late Sept/early Oct.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Through 18Z Tuesday...Cyclonic northerly flow has resulted in
plenty of strato cumulus clouds this aftn with MVFR cigs at
BTV/EFK/PBG and RUT with VFR at MPV/SLK and MSS. Expect mostly
VFR conditions at all sites by 20z this aftn with
north/northeast winds 5 to 10 knots. Overnight aviation
challenge is potential for low clouds or fog and associated IFR
conditions. Overall setup is not ideal for fog, given 10 to 15
knots near 500 feet, along with some weak cold/dry air
advection. Also, HREF continues to support idea of mid/upper
level clouds moving from west to east across our taf sites.
However, it did rain yesterday and sfc dwpts are currently in
the mid 40s, so feel cross over values will be reached in
several sites. Highest probability of IFR in fog/low cigs will
be SLK/MPV and EFK with VCFG at BTV/RUT possible. Any fog/low
clouds lifts by 13z with VFR conditions prevailing on Tuesday.

Outlook...

Tuesday Night: VFR. Patchy frost.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. Slight chance SHRA.
Friday Night: VFR. Slight chance SHRA.
Saturday: VFR. Slight chance SHRA.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$

WHAT HAS CHANGED...Danzig
DISCUSSION...Danzig/Taber
AVIATION...Taber