155
FXUS61 KBTV 272333
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
733 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 /00Z TUESDAY THROUGH SATURDAY/...
Through 00Z Wednesday...A few showers and thunderstorms continue
to periodically develop along the Adirondacks and Northeast
Kingdom of Vermont. Pulsing convection will drift east over the
next few hours and dissipate by about 02-03z. Some fog is
possible overnight, but some flow will remain at 500-1000 ft at
10-15 knots which should result in some mixing. These winds
appears strongest across northern New York. KEFK was directly
under a downpour, but most other terminals have received little
rain. So focused on climo favored spots with the most
pessimistic outlook for KEFK. 1SM is forecast at KMPV and KEFK
about 07z-11z, but may fall lower depending on how winds just
off the surface impact fog development. Fog will dissipate after
11z-12z with southeast winds 5 knots becoming 7-10 knots around
16-18z. Showers and thunderstorms will begin developing after
16-17z, generally moving south to north followed by a batch rain
21z-01z Wednesday. Convection could be widespread, and so
PROB30s are noted for most terminals as activity lifts north,
but there`s some uncertainty to the timing and focus of heaviest
rainfall. So we`ll tack down those details as we draw nearer.
Winds after 22z, trend back towards 4-8 knots and ceilings will
also be falling towards 3000-7000 ft agl.
Outlook...
Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday: Mainly MVFR, with areas VFR possible. Windy with gusts
to 30 kt. Likely SHRA, Slight chance TSRA.
Wednesday Night: Mainly MVFR, with local IFR possible. Likely
SHRA.
Thursday: Mainly VFR, with local IFR possible. Likely SHRA,
Slight chance TSRA.
Thursday Night: Mainly VFR, with local MVFR possible. Chance
SHRA, Slight chance TSRA.
Friday: Mainly VFR, with local IFR possible. Chance SHRA, Chance
TSRA.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. Slight chance SHRA, Slight chance TSRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Myskowski
DISCUSSION...Danzig/Myskowski
AVIATION...Haynes
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