343
FXUS61 KBTV 181827
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
227 PM EDT Fri Sep 18 2026

.WHAT HAS CHANGED...
As of 227 PM EDT Friday...

A frost advisory has been issued for portions of Vermont and
northern New York tonight and Saturday morning. Rainfall amounts
have increased slightly on Sunday.

&&

.KEY MESSAGES...
As of 227 PM EDT Friday...

1. Frost expected tonight across the Adirondacks and Northeast
Kingdom tonight. Gusty winds expected across Lake Champlain through
early Saturday morning.

2. Dry conditions continue on Saturday with widespread rainfall
expected on Sunday. Drier and cool weather to follow.

3. High pressure will dominate the region through much of next
week, with dry and below normal temperatures, with frost potential
in the climo favored areas

&&

.DISCUSSION...
As of 227 PM EDT Friday...

KEY MESSAGE 1: Gusty winds will continue across Lake Champlain through
2-4 AM on Saturday. Sustained winds may approach 25 knots at times
between 9 PM and midnight but winds will generally range from 20-23
knots. A few gusts closer to 30 knots will be possible, especially
following sunset, as a subsidence inversion helps to push the
stronger winds aloft closer to the surface. High pressure on
Saturday will help the pressure gradient relax and let winds
diminish to about 10 to 12 knots. Waves could be in the 2-4 ft range
through the remainder of the day with a persistent north wind in the
20+ knot range winds waves subsiding closer to 1-3 ft Saturday
morning.

Widespread frost across the Adirondacks and Northeast Kingdom is
looking increasingly likely as high pressure settles into the region
tonight. Winds initially will range in the 5-12 mph range this
evening but should go light by midnight. At the same time, dewpoints
will continue to fall as dry air advects into the region. With clear
skies and light winds, we should radiate out nicely with
temperatures plummeting as winds begin to relax. This will allow for
much of northern New York and the Northeast Kingdom to drop into the
lower to mid 30s which should facilitate frost formation. Outside of
these locations, it`ll still be noticeably chilly with lows in the
upper 30s to lower 40s.

KEY MESSAGE 2: A 1025 mb high pressure system will be anchored overhead
on Saturday with plenty of sunshine, light winds, and seasonably
cool temperatures expected across the region. However, Sunday is
looking like a much gloomier day with widespread rainfall expected
from mid-morning through the evening. Models have come into better
agreement with showing rainfall overspreading all over Vermont and
northern New York on Sunday while the exact rainfall amounts are a
bit more uncertain. Both the GFS and ECMWF keep the plume of deeper
moisture further south across the Mid-Atlantic while the NAM tries
to inject some of the nearly 2 inch PWAT values into Vermont. Given
the NAM boundary layer moisture bias, it`s feasible it`s much too
high on PWATs and the forecast is much closer to the GFS/ECMWF
solutions. This will bring widespread rain in the range of a third
of an inch to two-thitsdays of an inch with localized amounts upward
of an inch. Should the NAM forecast pan out, we could see double
those amounts. Even with the worst case scenario, rainfall rates and
amounts should be low enough that no flooding concerns are expected;
especially given the extended period of drier weather we have seen
over the past 30-45 days.

High pressure will build back in to begin the week with some gusty
north winds possible on Monday as the pressure gradient remains
tight. Winds will weaken throughout the day on Monday as high
pressure becomes further entrenched which could set the stage for
some fog Monday night.

KEY MESSAGE 3: A Rex block pattern will develop early to mid next week
as high pressure over the northern Great Lakes shifts east into
central Quebec, with troughing developing over the Mid-Atlantic.
Ridging associated with the high over Canada will nudge into
northern New England keeping us dry through mid next week with good
ensemble agreement in cold air damming across eastern Vermont. Clear
skies and subsidence under the ridge will draw seasonably cool air
south with highs in the 60s, and overnight lows in the low 30s to
the low 40s. Under the coolest nights if good radiational cooling
becomes more apparent, frost will be possible each night Tues-Thu in
the climo favored areas of the Adirondacks and central/northeastern
Vermont.

Towards the end of the work week next week, a coastal low off the
Mid-Atlantic will possibly open as it slowly tracks north towards
southern New England. Under the Rex Block, moisture from this system
may nudge slightly north, opening the door for light shower
potentials late week in our south and eastern zones Thursday and
Friday.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Through 18Z Saturday...VFR conditions are expected to persist for
most terminals through the entire TAF period. A drying cold front is
sweeping southeast from Canada with clearing skies. Few-Sct ceilings
around 5000ft agl, will trend towards SKC through the rest of the
day. Good vertical mixing is resulting in occasional gusty northerly
winds between 20- 25 MPH at all terminals. Highest gusts will be at
BTV/MPV with channeled north to south winds. An inversion will begin
to set up after 23Z which could help locally enhance gusts briefly
at BTV/MPV around 03Z, though winds overnight will trend calm by
sunrise, remaining light and variable into tomorrow. As the
inversion tonight develops, clearing skies may allow for some lower
ceilings at EFK/MPV, though confidence is low due to concurrent
lowering dewpoints behind the cold front. By sunrise, a lake cloud
over Lake Champlain may develop at or just south of PBG in a NE-SW
orientation, which may reduce cigs in the vicinity of PBG, though
the cloud should dissipate by 15Z, with all sites seeing clear skies
by the end of this TAF period.

Outlook...

Saturday Night: VFR. Chance RA.
Sunday: Mainly VFR, with local IFR possible. Definite RA.
Sunday Night: MVFR/IFR conditions possible. NO SIG WX.
Monday: Mainly VFR, with local MVFR possible. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Frost Advisory from 2 AM to 9 AM EDT Saturday for VTZ004.
NY...Frost Advisory from 2 AM to 9 AM EDT Saturday for NYZ029>031-
     034.

&&

$$

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