301
FXUS61 KBTV 162345
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
745 PM EDT Sun Aug 16 2026
.WHAT HAS CHANGED...
As of 217 PM EDT Sunday...
Increased thunder chances during the midday and afternoon hours
on Monday, but severe t-storm potential remains low.
&&
.KEY MESSAGES...
As of 217 PM EDT Sunday...
1. Widespread showers overnight, with separate development of
showers and some embedded thunderstorms midday/afternoon Monday.
2. Seasonable conditions persist through the second half of the
week with mainly dry weather Thursday into Saturday.
&&
.DISCUSSION...
As of 217 PM EDT Sunday...
KEY MESSAGE 1:
High clouds are in the process of increasing from west-to-east
across northern New York and Vermont this afternoon, associated
with mid-level trough extending from northern Ontario southward
across Lake Huron, Lake Erie and into Ohio. PBL winds have
turned southerly with 1022mb sfc anticyclone now east of Cape
Cod. Southerly winds should remain moderate overnight with
approaching frontal system and absence of much radiational
cooling overnight. Overnight lows will generally range from the
low-mid 60s. With the increasing southerly gradient flow, a Lake
Wind Advisory has been posted (see Marine section below for
tonight. The Lake Wind Advisory may be necessary through the
morning hours on Monday as well.
Not much in the way of mid-tropospheric height falls overnight,
but some low-level WAA in advance of the approaching front
should be just enough to yield scattered rain showers overnight,
especially after 03Z or so. There is some marginal elevated
CAPE for parcels lifted from 850-775mb per HRRR and NAM3
forecast soundings. As such, kept with the idea that there could
be a few embedded convective elements with a few overnight
rumbles of thunder possible. PoPs are highest across central/nrn
VT during the pre-dawn hours (70-80%) and generally 30-50%
elsewhere.
Heading into Monday...surface boundary progresses through
slowly from west to east. If we get some breaks in the cloud
cover, there is a chance for modest PBL destabilization by late
morning/early afternoon. Consistent with this, the 12Z HRRR
developed 500-800 J/kg SBCAPE during the peak heating hours
Monday, that is relatively uncapped. Anticipating a separate
broken line of showers - and perhaps a few embedded
thunderstorms - to develop during the midday hours while
drifting slowly ewd across central/ern VT by mid-late afternoon.
Weak mid-level lapse rates and modest sfc-6km shear suggest
that if thunderstorms form, they are unlikely to become severe.
However, have shown a separate period of 60-70% PoPs to account
for this expected separate period of convective showers and
storms during Monday afternoon. High temperatures on Monday will
be seasonable to slightly below average for mid-August, in the
mid- upper 70s.
KEY MESSAGE 2: Lingering showers will move out on Wednesday
night and Thursday as broad cyclonic flow slowly migrates
eastward. After the system moves off, a period of drier weather
looks to return for the latter half of the week. Daytime
temperatures increase towards climatological normals into next
weekend with highs in the 70s and lower 80s as well as overnight
lows falling into the 40s and 50s. There is the potential for
another system to sweep through next weekend bringing some
sustained showers. We`ll continue to monitor this potential as
the event approaches.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Through 00Z Tuesday...Widespread showers tonight will be
followed by scattered showers and localized thunderstorms
Monday. As rain showers arrive tonight, we`ll see a general
trend towards MVFR or lower ceilings, reaching widespread MVFR
cigs by 01Z-04Z Monday. Winds should persist out of the south,
with sites MSS and SLK picking up a more southwesterly component
around 05Z-08Z. Southerly flow will likely remain channeled and
gusty through the Champlain Valley, gusting 20-25 knots at site
BTV throughout the night tonight and early Monday morning. IFR
ceilings are possible sometime tonight and into Monday morning
as well, though some uncertainty remains. Most likely spots for
IFR ceilings will be SLK and MSS with that southwesterly wind,
though no site is out of the question. Most model soundings are
not as saturated as probabilistic data might suggest. As the
showers approach and we get additional observations from areas
upstream, this may increase confidence in one direction or
another.
Outlook...
Monday Night: Mainly VFR, with local IFR possible. Slight chance
SHRA.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: Mainly VFR, with local MVFR possible. Likely SHRA,
Slight chance TSRA.
Wednesday Night: Mainly VFR, with local MVFR possible. Slight
chance SHRA.
Thursday: VFR. Slight chance SHRA.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. NO SIG WX.
&&
.MARINE...
As of 217 PM EDT Sunday...
A Lake Wind Advisory has been posted for Lake Champlain tonight. A
sharp increase in southerly gradient flow is expected this evening,
with sustained winds 20-30kt over the broad lake through the
majority of the overnight hours. The Great Lakes Wave Model
indicates max wave heights of 3-4 ft between 06-14 UTC from near
Colchester Point to east of Valcour Island, which appears reasonable
based on expected southerly sustained wind speeds. Should see
those wind speeds lessen after noon on Monday.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.
&&
$$
WHAT HAS CHANGED...Banacos
DISCUSSION...Banacos/Storm
AVIATION...Neiles
MARINE...Banacos
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