156
FXUS61 KBTV 291902
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
302 PM EDT Tue Sep 29 2026

.WHAT HAS CHANGED...
As of 302 PM EDT Tuesday...

Chances for scattered showers Thursday afternoon/evening have
increased in much of northern New York and northern Vermont.

&&

.KEY MESSAGES...
As of 302 PM EDT Tuesday...

1. Warmer and sunnier mid week, with sharply rebounding
temperatures following a cool and cloudy start to the week.

2. Shower chances return Thursday afternoon and continue into
Friday ahead of a cold front.

3. A progressive pattern aloft will result in a series of cold
fronts sweeping across our region this weekend into early next week
with temperatures trending below normal.

&&

.DISCUSSION...
As of 302 PM EDT Tuesday...

KEY MESSAGE 1: Satellite imagery shows stratus eroding and becoming
stratocumulus across much of northern New York and portions of
central Vermont, especially southeast of the higher peaks
leading to only localized patches of blue sky this afternoon. A
sharper clearing line is still well to our north and west near
the Ottawa Valley; these trends suggest skies will clear near
the International Border towards sunset. Overall, this setup
leads to a challenging sky cover forecast overnight. The
clearing timing will delay fog formation, but think because
dewpoint depressions are so small today, it won`t take long for
temperatures to pass their crossover values. As such, the
thinking is mostly unchanged with regards quite a bit of fog to
develop especially after midnight, with relatively late timing
in central/northeastern Vermont. However, continued light
north- northwesterly flow may help maintain clouds and limit fog
in some areas that typically see fog, such as the Upper Valley
in Vermont.

With mainly clear skies aside from aside from a large veil of
high clouds associated with a plume of deep moisture blowing off
from convection in the southwestern US, it will be a much milder
day on Wednesday. High temperatures expected to be a few to
several degrees above normal, ranging from the upper 60s to mid
70s. Aside from the localized stronger south winds on Lake
Champlain, winds will be rather light as the center of high
pressure shifts to our southeast.

KEY MESSAGE 2: Sunshine will be more variable on Thursday as we
get under the influence of the first of a few waves of low
pressure extending from the closed upper level low that will
have been responsible for excessive rain across a swath of the
southwestern US into the central Plains states. The bulk of the
rain we see from this system is on track to come through on
Friday. However, most model guidance now shows some showers
moving eastward through the Adirondacks and northern Vermont
Thursday afternoon into the evening, likely driven by isentropic
lift in a moistening warm advection pattern. Have trended PoPs
upward and added some spotty measurable rain amounts for this
period, but with the air mass being a modified tropical one, the
environment will become favorable for efficient rainfall.

No indications for particularly heavy rain were noted, but warm
rain processes will support downpours and locally higher
rainfall amounts. This applies for both Thursday
afternoon/evening and again Thursday night into Friday as a cold
front sharpens to our west and pushes through. The front still
looks to cross relatively quickly during the Friday morning
hours. As a result, there is a fairly large spread in possible
temperatures on Friday given the impact of both cloud cover and
cold air advection as the system pushes through. Generally we
can expect a cooler day in our northern/western areas, while
central and southern portions of Vermont may see temperatures
just as warm as Thursday, reaching the mid or upper 70s.

KEY MESSAGE 3: The large scale pattern supports a mean mid/upper lvl
trof developing across the Great Lakes into the NE CONUS for late
weekend into next week, which wl produce below normal temps and
mostly mtn precip chances. The highest probability of measurable
precipitation wl be favorable nw upslope areas of the northern Dacks
and central/northern Greens on Monday. The latest trends for Sunday
precip shows an area going to our north, closer to the better
forcing and another patch of precip sliding to our south. However,
still thinking chc probability in the 30-40% range is reasonable
from WPC this aftn. However, pops on Monday/Monday night probably
need to be doubled from WPC, especially with a period of favorable
upslope flow and strong llvl caa. The window is limited as flow
aloft is progressive and the closed circulation is well north of our
cwa, while best deep layer moisture is south and east of our fa. The
big story going into next week wl be the window of much below normal
temps with progged 850mb temps btwn -5C and -8C off the latest 12z
GFS and sub-530 dam thickness values acrs our fa. Latest WPC
guidance shows temps in the mid 50s to lower 60s on Monday and
mostly 50s for Tues with lows 30 to 45F Monday night and 23F at SLK
to upper 30s near Lake Champlain. Early guidance indicates this
could be the coldest airmass of the fall season impacting our cwa
early next week. However, as flow remains progressive with no deep
amplification, warmer air redevelops by the middle of next week
again.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Through 18Z Wednesday...A mix of MVFR and IFR conditions will
trend toward MVFR/VFR in the next 1 to 2 hours, as drier air
aloft mixes toward the surface and ceilings slowly improvement.
Highest probability of lingering MVFR cigs will be
BTV/MPV/EFK/RUT and SLK with VFR at MSS/PBG. Expecting a mix of
stratus/fog to redevelop across our taf sites btwn 02-04z this
evening, as boundary layer moisture associated with cyclonic
blocked flow will result in widespread IFR/LIFR conditions
developing. Highest probability (80-90%) of IFR/LIFR is at
SLK/MPV/EFK with likely probability (60-70%) of intervals of
IFR/LIFR at BTV/RUT/MSS, with chance of brief fog/stratus
toward sunrise at PBG as winds shift to the southeast.
Otherwise, any fog/stratus should lift btwn 13-15z on Weds as
winds shift to the south/southwest at 4 to 8 knots.

Outlook...

Wednesday Night: VFR. NO SIG WX.
Thursday: Mainly VFR, with local MVFR possible. NO SIG WX.
Thursday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Friday: Mainly VFR, with areas MVFR possible. Likely SHRA.
Friday Night: Mainly VFR, with local MVFR possible. Chance SHRA.
Saturday: VFR. NO SIG WX.
Saturday Night: VFR. NO SIG WX.
Sunday: VFR. Slight chance SHRA.

&&

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

&&

$$

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