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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBTV 081726
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
126 PM EDT Sat Aug 8 2020

.SYNOPSIS...
Scattered showers and thunderstorms will develop across the higher
elevations of the Green and Adirondack Mountains this afternoon.
These showers will taper off this evening with loss of heating and
drier weather will continue tonight and Sunday. A warming trend will
start on Sunday as highs warm into the lower to mid 80s. We could
see places in the Champlain and St. Lawrence Valley push 90 degrees
once again as early as Monday with above normal temperatures
expected through next week. Drier weather will continue through the
first half of next week before wetter and unsettled weather makes a
return on Wednesday.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 942 AM EDT Saturday...Cluster of thunderstorms with
locally heavy rainfall currently weakening and slowly exiting
southern portions of Rutland/Windsor Counties. MRMS/HPE 3 hourly
estimates along with surface observations suggest totals up to
2.5 inches have occurred in this area since 600 am and a Special
Wx Statement for localized flooding remains in effect until 10
am. Any flooding should be isolated and minor, if it does occur.
As such, increased PoPs and cloud cover in this area through
late morning as activity exits. Otherwise, going forecast
remains in decent shape with a partly to mostly sunny skies,
seasonably warm temperatures, modest humidity and a few late
afternoon showers/storms. Latest CAM output suggests highest
probabilities of a late day storm to occur along the western
Lake Champlain lake breeze in eastern Clinton/Essex Counties, NY
where convergence occurs with light westerly geostrophic flow
aloft along with a modest low level upslope component. Have a
great day!

Previous Discussion...
A few showers moved across southern Vermont as weak PVA led to
some decent upward vertical motions. However, the environment
has remain highly capped leading to these showers to be short-
lived and very light in nature. We will see any lingering shower
activity shift eastward shortly after sunrise as a shortwave
trough swings through the region. Another very nice summer
afternoon is in store for the North Country as we see partly
sunny skies prevail across the region with highs once again in
the upper 70s to lower 80s. We will see some showers and
possibly a thunderstorm or two form over the high peaks of the
Adirondack and Green Mountains today as we have a pocket of
colder air aloft underneath the aforementioned shortwave trough.
With the colder air aloft, our lapse rates this afternoon will
aid in creating a few hundred J/kg of CAPE. While we could see a
few of these thunderstorms ultimately become rooted in the
boundary layer, a loft of the instability will remain elevated.
This basically means we could have some brief moderate rainfall
and a few rumbles of thunder without the concern of any hail or
strong wind gusts. Any convection that does fire this afternoon
will quickly dissipate this evening with the loss of diurnal
heating. Quieter weather is expected tonight and again on Sunday
as a weak shortwave tracks just north of the international
border. Temperatures warm into the lower to mid 80s on Sunday
which looks to be the first day of a warming trend as we head
into next week.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
As of 346 AM EDT Saturday...A compact shortwave will skirt the
northern part of the forecast area Sunday night, so can`t rule
out a shower or two overnight near the Canadian Border. The rest
of the forecast are should remain dry overnight. Lows will be
in the low to mid 60s. Once the shortwave moves downstream by
midday Monday, increasing heights will keep the area mainly dry
for the remainder of the day with the exception of a few showers
possible over the northern Adirondacks. No large-scale forcing
present, however will see warm air advection and moisture
advection through the day on westerly flow, which will increase
instability to the point where a few showers may be able to pop
up over higher terrain once the ridge axis moves to our east.
Highs Monday will be in the mid to upper 80s.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 346 AM EDT Saturday...Flow turns increasingly southwesterly
Tuesday, ushering in warmer, moist air from the Ohio River
Valley to the North Country. Will see increasing instability
Tuesday as temperatures rise to near 90 and dewpoints rise into
the upper 60s/low 70s. Focused forcing for ascent arrives
Tuesday night as a front moves crosses the forecast area from
west to east. At this point, it looks like the front will move
through overnight, which will limit instability and decrease the
t-storm potential. However, if the timing shifts either way,
could see an increase in t-storm threat. Deep layer shear is
marginal, so not expecting any organized severe storms
regardless of the exact timing of the frontal passage. The front
may stall over our forecast area into Wednesday, and if the
boundary remains overhead Wednesday afternoon, would see a
better chance for some (mainly non-severe) t-storms. However, if
the boundary were more progressive, chances for showers and
thunderstorms Wednesday would decrease.

The remainder of the week is a bit tricker to forecast, as the area
will remain close to the border between Canadian high pressure to
our north and more unsettled and unstable conditions to our south.
It continues to appear that we will remain on the northern side of
this boundary...thus have kept the forecast mainly dry to finish out
the work week...however this may change if the boundary were to
shift northward into our forecast area.  Higher confidence in dry
weather in the northern part of our CWA, slightly lower confidence
in dry weather over southern VT.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Through 18Z Sunday...Mainly VFR through the TAF period. SCT/SKC
conds expected through 07Z with cumulus bases in the 050-080 AGL
range. An isolated shower/storm possible through 01Z across
elevated terrain, but paucity of coverage warrants no mention in
the terminal forecasts at this time. SCT/BKN mainly mid-level
cigs in the 070-150 AGL then arrive after 07Z Sunday with an
outside shot of a shower at KMSS after 14Z. Some brief MVFR/IFR
br/fg possible at KMPV/KSLK in the 07-12Z time frame but
confidence only moderate. Winds generally variable and less
than 10 kts through the period, governed heavily by terrain
and/or lake breeze flows.

Outlook...

Sunday Night: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
Monday: Mainly VFR, with local MVFR possible. Slight chance SHRA,
Slight chance TSRA.
Monday Night: VFR. Slight chance SHRA.
Tuesday: VFR. Likely SHRA, Slight chance TSRA.
Tuesday Night: VFR. Chance SHRA.
Wednesday: VFR. Slight chance SHRA, Slight chance TSRA.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. Slight chance SHRA, Slight chance TSRA.

&&

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

&&

$$
SYNOPSIS...Clay
NEAR TERM...Clay/JMG
SHORT TERM...Duell
LONG TERM...Duell
AVIATION...JMG