251
FXUS61 KBTV 201746
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
146 PM EDT Sun Sep 20 2026

.WHAT HAS CHANGED...
As of 249 AM EDT Sunday...

No significant changes made with this forecast package.

&&

.KEY MESSAGES...
As of 249 AM EDT Sunday...

1. Light rain and cool temperatures today, then a prolonged dry
and seasonably cool weather stretch begins.

2. Dry weather persists through mid week, though we will need
to monitor for increasing shower chances from Friday onward.

&&

.DISCUSSION...
As of 249 AM EDT Sunday...

KEY MESSAGE 1: A widespread light rainfall event remains on track for
today. There has been a slight trend towards less rainfall and
shorter duration of rain, as well as lower chances for rain in the
St. Lawrence Valley. That being said, the forecast generally is
pretty consistent with observations so far early this morning.
Moisture advection from the south and southwest, particularly from
the surface up to 700 millibars, is occurring with a sharp gradient,
while westerly mid-level/upper level is present. An inverted trough
in northern New York and weak surface low sliding eastward across
northern Pennsylvania will support modest southeasterly winds across
the Champlain Valley and points east.

Stratiform rain will blossom in northern New York and gradually
expand east-northeastward this morning. During the afternoon,
the area of rain will contract from west to east and towards the
southeast as the 850 millibar trough axis and associated low
level convergence and lift exits. Rainfall rates will be 0.01 -
0.05" for most of the event, but up to a few hours intensity
will likely increase and reach the 0.1"-0.15" range (typically
considered "moderate" rather than light). These moderate
rainfall rates are favored from the Adirondacks eastward over
most of northern Vermont at times from about 10 AM and 3 PM. As
a result, event totals, as they would be for a winter weather
event, are somewhat uncertain but should be mostly in the 0.25"
to 0.5" range within much of the region.

Temperatures today will generally be chilly in the low to mid 50s
with thick clouds and rain for much of the day, and even cooler in
portions of central/eastern Vermont due to the aforementioned
upslope easterly component to the wind. It is a tricky hourly
temperature forecast with large dependence on rainfall timing;
as a result, there is potential for late day highs where rain
ends early enough and morning highs in northern and eastern
portions of Vermont prior to rain arriving.

Tonight we`ll lock in some low clouds and patchy fog ahead of a
moisture starved cold front arriving from the northwest. Once
this boundary passes through, northerly flow will develop with
some low clouds slow to clear out, especially in the vicinity
of the higher terrain with moist 925-850 millibar air expected
to linger into the day. Clouds should gradually scatter
generally from north to south, leading to the beginning of a
prolonged stretch of primarily clear skies. Fog chances in climo
favored areas will begin high Tuesday, but tend to decrease
each morning following days of drying after Sunday`s rainfall.
Temperatures will remain below normal through Wednesday with the
dominance of strong high pressure to our north supplying us
with seasonably cool air.

KEY MESSAGE 2: The blocking pattern will remain in place much of next
week, with high pressure centered to our north while low pressure
develops off the Mid Atlantic. While our weather will be pleasant,
temperatures will likely remain below normal, with daytime highs
mainly in the 60s. Clear skies and light winds will allow for chilly
overnights, and patchy frost will be possible in the
Adirondacks/eastern VT valleys each morning. While confidence has
increased in the dry weather persisting through Thursday, low
pressure meandering around off the East Coast will keep the threat
of showers around as we head toward the weekend, especially in
southern/eastern VT. Have stayed with the NBM/WPC forecast for
Friday onward given the spread in model solutions for mid/late next
week.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Through 18Z Monday...A wide range in flight conditions this
afternoon from IFR at SLK/BTV to MVFR at MPV/RUT/EFK/MSS and
VFR at PBG. Expecting variable conditions between MVFR/IFR at
MPV/SLK thru 00z with brief IFR possible at BTV/EFK, while
mostly a combination of MVFR/VFR at PBG/MSS and RUT. After
sunset expecting the onset of fog/br and associated IFR/LIFR to
occur pretty quickly, given recent rainfall and light winds.
However, a secondary cold front pushes across our region between
06z-09z, expect areas of fog/br to transition into IFR cigs with
MVFR vis, as low level stratus develops under blocked flow and
low level northerly flow. Highest probability (60-70%) of long
duration 8-14 hours)of IFR/LIFR is at SLK/MPV/RUT, with medium
confidence (40-60%) at BTV/EFK and intervals of IFR or lower
conditions possible at MSS/PBG. Greatest potential for fog at
most sites will be between 02-08z this evening, with more
stratus likely after 08z, especially mountain sites and east
side of CPV. Conditions are slowly improving to MVFR by 15z and
mostly VFR by 18z Monday. South/southeast winds become light
this evening and shift to the north/northwest after 06z tonight
and increase 5 to 10 knots by sunrise.

Outlook...

Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.

&&

.MARINE...
As of 249 AM EDT Sunday...

Expect south-southeast winds this morning to ramp up but remain
below Lake Wind Advisory criteria, peaking around 9 AM just
above 20 knots in the vicinity of Colchester Reef before
settling into the 15-20 knot range during the rest of the day.
Waves should build up to 3 feet.

Following a lull in winds tonight, a favorable setup for well
mixed northerly winds will develop for Monday when a Lake Wind
Advisory may be needed. Waves could build up to 3 to 4 feet over
the southern waters during the Monday morning period associated
with these gusty north winds.

&&

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

&&

$$

WHAT HAS CHANGED...Kutikoff
DISCUSSION...Kutikoff/Hastings
AVIATION...Taber
MARINE...Kutikoff