848
FXUS61 KBTV 271847
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
247 PM EDT Mon Jul 27 2026

.WHAT HAS CHANGED...
As of 247 PM EDT Monday...

The forecast for the mid-week rain and flood threat remains about
the same.

&&

.KEY MESSAGES...
As of 247 PM EDT Monday...

1. Widespread showers and thunderstorms will occur Tuesday
through Thursday as a slow-moving system tracks through, bringing
the potential for localized flash flooding.

2. Unsettled weather continues into the weekend with the
approach of another developing mid to upper level trough.

&&

.DISCUSSION...
As of 247 PM EDT Monday...

KEY MESSAGE 1: An upper-level low builds into the region tomorrow and
remains over the area into Thursday. An associated surface low will
form over the Great Lakes and occlude as it moves into New York and
New England, bringing consistent showers. The showers enter northern
New York tomorrow morning and enter Vermont tomorrow afternoon as a
south to north oriented line. There will be some convective
enhancement on the frontside, due to surface CAPE reaching up to
around 1,000 J. A lack of deep-layer is expected to prevent any
severe threat. These storms will likely have the highest rainfall
rates of the entire event, but dry antecedent conditions and some
south to north storm motion should keep the flood threat relatively
low for the day on Tuesday. The axis of rain looks to become more
sse-nnw oriented heading into Tuesday evening and night, and east to
southeast flow will develop. While the precipitation should trend
toward more stratiform as the night goes on, some convective
enhancement will still be likely, especially in southern Vermont
where the highest totals are expected. This Tuesday night into
Wednesday morning would likely have the highest concern for any
flash flooding as the axis of rain looks to stay relatively
stationary. Heading through Wednesday, the dynamics weaken and the
axis of rain looks to become more broken and lighter. Periods of
showers will continue Wednesday night through Thursday, but they
will become much lighter and gradually less widespread as the
surface low weakens and pushes east. The area of highest concern is
the eastern slopes and spine of the southern Green Mountains where
the best dynamics will combine with upsloping. The east slopes of
the Adirondacks will likely be the second area of focus due to the
upsloping. Still, in the more favored areas, only isolated flash
flooding looks to be possible. The Champlain Valley and Northeast
Kingdom will likely receive some locally lower totals due to
downsloping.

KEY MESSAGE 2: An unsettled weather pattern will continue into the
weekend as our approaching system slowly departs Friday with an
additional system possibly arriving sometime late into the weekend.
There is still a large spread in timing of the departure of our
approaching system and the weekend system, but trends have moved
towards lingering showers and embedded thunderstorms Friday, with a
more delayed trend in the weekend activity, perhaps closer towards
Monday next week. Models denote cyclonic circulation lingering to
our south and east Friday with continued wrap around moisture in
portions of eastern Vermont. With easterly flow blocked against the
Greens, a differential heating boundary between the cooler eastern
Vermont and warmer Champlain Valley and northern New York may set
up. This will lead to areas of shower development along the
convergence boundary Friday afternoon potentially.

Weak ridging tries to build into our cwa for Saturday, before
another shortwave, associated with a 700-500mb trof approaches from
the Great Lakes. Model ensembles in the GEFS and GEPS denote a more
delayed system evolution closer to Sunday or Monday, with more
isolated to scattered terrain showers Saturday afternoon. This is
line with abundance of subsidence that may be across the area as our
current system occludes and subsides over southern New England late
this week. Latest guidances shows Saturday highest potential over
northern NY, while Sunday activity wl be more widespread impacting
both VT and NY. Limited run to run continuity and large spread in
potential solutions results in low forecaster confidence and
associated predictability on probability and timing of precip,
especially Sunday into early next week. Temps will be driven by
clouds/precip, but mostly above normal values anticipated,
especially at night with lows in the upper 50s to upper 60s, while
highs range from the mid 70s to mid 80s. Some levels of humidity are
expected, but the probability of much above normal temps or
significant heat is low given the anticipated pattern.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Through 18Z Tuesday...Most terminals through the next 18 hours should
remain VFR, outside of MSS/SLK/MPV. Isolated to scattered showers
and thunderstorms will develop along the higher terrain of the
Adirondacks and spine of the Greens this afternoon and drift east
into the area valleys. Some thundershowers have already formed east
of the St. Lawrence River and are drifting twoards MSS. Expectations
are these will reach the terminal around 20Z with an hour on each
side of VCTS. Have included a TEMPO for these thunderstorms. Within
any thunderstorms, main impacts will be visibility reductions to
MVFR with brief IFR possible, though IFR confidence is low at this
time. Outside of MSS, have included a PROB30 groups for thunderstorm
chances at SLK/PBG/MPV/EFK from 19-24Z generally. Best chances for
any terminal to see a thunderstorm or VCTS will be at MSS/SLK.
Storms will be pulse like and generally brief, but will have the
chance for localized heavy downpours. Tonight will feature broken
ceilings to around 7-10kft. Should SLK or MPV receive rain,
especially if close to sunset, fog probabilities will increase. Have
included a 5SM BR at SLK and MPV from 06 and 08Z, respectively,
until 11Z with persistence forecasting in mind based on last night.
Limitations tonight will be a subtle southerly wind which may hold
fog at bay for portions of the night. Should rain fall close to
sunset, early fog development closer to 04-05Z may be possible.
Conditions become more changeable tomorrow morning with the approach
of a strong system. Showers and embedded thunderstorms are expected
tomorrow morning into the early afternoon for MSS/SLK/PBG and
perhaps BTV by the end of this TAF package.  Winds today will be
under 10 knots, and generally variable, outside of any potential
thunderstorm activity. Winds will turn light to calm from the south,
becoming more southeasterly into the daylight hours tomorrow morning

Outlook...

Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday: Mainly MVFR, with areas VFR possible. Definite SHRA,
Chance TSRA.
Wednesday Night: Mainly MVFR, with local IFR possible. Chance
SHRA.
Thursday: Mainly VFR, with local IFR possible. Likely SHRA,
Slight chance TSRA.
Thursday Night: Mainly VFR, with local IFR possible. Slight
chance SHRA, Slight chance TSRA.
Friday: MVFR/IFR conditions possible. Slight chance SHRA, Slight
chance TSRA.
Friday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Saturday: Mainly VFR, with local MVFR possible. Slight chance
SHRA, Slight chance TSRA.

&&

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

&&

$$

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