190
FXUS61 KBTV 292346
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
746 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 /00Z WEDNESDAY THROUGH SUNDAY/...
Through 00Z Thursday...Conditions are currently a mix of VFR and
MVFR, mainly due to 1000-2500 ft agl ceilings, but there is some
evidence of drizzle near KEFK with 3SM visibility and running up
to the TAF due time, there have been some 600-900 ft decks
starting to come up. Changeable conditions are possible over
the next 3-6 hours. Some partial clearing is expected to take
place, but any clearing could easily give way to fog formation.
For the most part probabilities of IFR based of NBM guidance
suggests mostly 10-30% chances before 04z, and then ramping up
into the 60-80% chance realm from 06z-13z. So most terminals
have either gradually falling ceilings towards 700-1200 ft agl
and some mixture of 1-5SM visibility. Winds overnight will
mostly be light and variable. Gradual improvement is likely, and
most locations should be near or at VFR conditions after 18z.
Outlook...
Wednesday Night: VFR. NO SIG WX.
Thursday: Mainly VFR, with local MVFR possible. Chance SHRA.
Thursday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Friday: Mainly MVFR, with areas VFR 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...Taber/Kutikoff
AVIATION...Haynes
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