654
FXUS61 KBTV 081826
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
226 PM EDT Sat Aug 8 2026
.WHAT HAS CHANGED...
As of 223 PM EDT Saturday...
Have increased chances for precipitation slightly on Sunday on
northern and western slopes of the Adirondacks as well as
northern Vermont along the international border due to cold
pool/upslope type rain showers and thunderstorms. Have also
incorporated patchy fog in valley locations to the forecast
tonight and Sunday night.
&&
.KEY MESSAGES...
As of 223 PM EDT Saturday...
1. Intervals of showers and thunderstorms will continue this
afternoon and evening. Warm and humid conditions will persist
through much of the weekend.
2. Chances for heavier showers and thunderstorms continue to
look likely Monday into Tuesday as a shortwave pushes through the
region.
3. Unsettled weather continues Wednesday onward, and
temperatures trend slightly below normal by the weekend.
&&
.DISCUSSION...
As of 223 PM EDT Saturday...
KEY MESSAGE 1: A large, closed upper low over Hudson Bay in Canada will
send a prefrontal trough shortwave through northern New York and
Vermont this afternoon, arriving into a warm, humid air mass with
temperatures in the upper 70s to mid 80s. This will result in likely
showers and thunderstorms over the next several hours, most
widespread across the Champlain Valley and northern Vermont. Severe
weather is not expected from these storms with minimal shear
available, though any shower or storm could produce heavy rainfall
with precipitable water values 1.50-1.75 inches and slow storm
motions. Locations that have received heavy rainfall already in the
past 24 hours will be particularly at risk for flooding and ponding
of water in low lying spots. Precipitation should wane overnight
tonight, but chances remain across northern New York and northern
Vermont for additional heavy showers and embedded rumbles of thunder
as a cold front moves through the region (20-60% precip chances).
Lows tonight will remain mild ahead of the front in the upper 50s
and 60s. A brief break in the unsettled pattern is expected to
develop throughout the day Sunday as a narrow axis of high pressure
and drier air move over the region, though high temperatures will
remain warm in the upper 70s to mid 80s and there is the chance of a
shower or two with embedded rumbles of thunder (20-50% chance
precip) on northern and western slopes of the Adirondacks as well as
northern Vermont along the international border. Sunday night,
temperatures should fall back towards seasonal normals in the 50s to
mid 60s.
KEY MESSAGE 2: We remain in the cyclonic flow of the closed upper low
over Hudson Bay in Canada early next week, and another shortwave is
expected to drive through northern New York and Vermont Monday and
Monday night. This will likely produce precipitation across northern
New York Monday afternoon, expanding to Vermont during the
evening/overnight hours (50-90% chance precip). Highs both Monday
and Tuesday will be in the mid 70s to mid 80s, resulting in the
potential for showers and thunderstorms. Once again, wind shear is
looking unimpressive (limited severe threat), but moisture will
advect back in from the Great Lakes with modeled Pwats 1.50-1.75"
returning. We`ll be monitoring this period for flooding potential,
particularly Monday evening.
KEY MESSAGE 3: The unsettled weather pattern will continue for the
second half of the week. In general, expect intervals of showers
and thunderstorms interspersed with drier days and a trend
towards slightly cooler temperatures towards the weekend.
The midweek timeframe will feature progressive zonal flow that will
send a series of quick-moving systems through our area. Despite the
numerous chances for rain, hydro concerns are low given the expected
progressive movement of the systems. For Wednesday and Thursday, the
best chances for showers (and possibly a few embedded thunderstorms)
will be during the afternoon hours as marginal instability develops.
Looking towards the end of the week, the upper-level flow will
amplify as ridging builds over the western US with downstream
troughing over the eastern US/Canada. The cyclonic flow over the
northeastern US will favor a continuation of scattered showers
with slightly below normal temperatures for the weekend.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Through 18Z Sunday...Scattered showers with a few embedded
thunderstorms will increase in coverage this afternoon, peaking
between 18Z and 22Z. Any thunderstorms that do materialize will be
pulse-like in nature, and are not expected to last long. Given the
isolated coverage and brief duration of individual storms, have left
mention of thunderstorms out of all TAFs at this point. However,
will be watching radar closely and will amend to include tstorms if
terminals are expected to be impacted. Any thunderstorms or showers
that do go over a terminal may briefly bring MVFR/IFR visibilities
and MVFR ceilings, but outside of precipitation conditions are
expected to remain predominantly VFR.
Overnight tonight, expect ceilings and visibilities to lower as
a mix of low stratus and mist/fog develops. Forecast soundings
suggest fog is most likely in climatologically favoured valleys
of central and eastern Vermont, where low-level winds will
remain lighter than over northern New York. Meanwhile, an area
of stratus looks likely to develop over northern New York,
especially over the northern Adirondacks after 06Z. Just how
expansive the stratus will get is lower confidence, and for now
have just introduced a SCT003 layer at KMSS. However, there is
the possibility that KMSS could also see a period of IFR or LIFR
ceilings mainly between 06Z and 12Z. The overnight stratus and
fog is unlikely to affect the Champlain Valley terminals, and
have forecasted VFR conditions overnight for KBTV, KPBG, and
KRUT.
Outlook...
Sunday Night: VFR. NO SIG WX.
Monday: VFR. Slight chance SHRA, Slight chance TSRA.
Monday Night: Mainly VFR, with local IFR possible. Likely SHRA,
Slight chance TSRA.
Tuesday: Mainly VFR, with local IFR possible. Slight chance SHRA,
Slight chance TSRA.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. Chance SHRA, Slight chance TSRA.
Wednesday Night: Mainly VFR, with local MVFR possible. Chance
SHRA, Slight chance TSRA.
Thursday: Mainly VFR, with local MVFR possible. Chance SHRA,
Chance TSRA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Storm
DISCUSSION...Storm/Duell
AVIATION...Duell
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