318 
FXUS61 KBTV 150528
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
128 AM EDT Sun Aug 15 2021

.SYNOPSIS...
High pressure drifting over the North Country will bring us
drier and slightly cooler weather that will last through 
Tuesday morning. The weather will then turn more unsettled from 
Tuesday afternoon onward once the high pressure moves to our 
east and return southwesterly flow develops. Temperatures and 
mugginess will increase each day through the end of the week, 
along with the return of afternoon showers and thunderstorms.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 124 AM EDT Sunday...No changes needed with this 
update. Some isolated stratus over the high terrain is visible 
on satellite otherwise skies are clear across the North Country.
Latest RAP MSLP analysis shows gradient beginning to slacken 
therefore expect winds to continue to diminish over the next 
couple hours. Still thinking some pockets of patchy valley fog 
are possible. Overall, a pleasant mid August night is on tap.

Previous Discussion...A very quiet period of weather is 
starting this afternoon behind this morning's frontal passage. 
In the wake of the front, expansive surface high pressure will 
build in, allowing for subsidence to develop. Main forecast 
challenge is potential for fog development overnight. Plenty of 
moisture at the surface from this morning's rainfall despite the
drier air mass moving overhead, and with clear skies tonight, 
thinking we will see some patchy fog develop. Limiting factor 
will be light sustained northwesterly flow just off the surface,
which will keep enough mixing in place to limit coverage of fog
to sheltered valleys. Overnight lows tonight will be in the 
upper 40s to mid 50s...substantially cooler than the lows the 
previous few nights. Conditions will also be noticeably less 
muggy than our recent weather. 

For Sunday, looking continued quiet and dry with persisting subsidence
under high pressure. Will just see some shallow fair- weather cumulus
clouds develop in the afternoon and highs in the low to mid 70s.
Lows Sunday night will again be in the upper 40s to mid 50s.

&&

.SHORT TERM /MONDAY NIGHT/...
As of 344 PM EDT Saturday...Expect sunny weather with no
precipitation for another day due to dry air at all levels of the
troposphere as sprawling high pressure remains over the area.
Towards daybreak, the leading edge of a warm front will approach the
southern portions of North Country, so they should see a layer of
low clouds roll overhead. Elsewhere, only thin, high clouds may make
an appearance late. Temperatures will be near normal for mid August
with highs ranging from 75 to 80 and lows in the 50s in most
locations.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 344 PM EDT Saturday...Isolated to scattered showers and a
rumble of thunder will be mainly over the Adirondacks westward 
into the St. Lawrence Valley on Tuesday. Farther east, upper-
level support for precipitation will be weaker and in the 
absence of deep moisture, expect mainly dry conditions over 
Vermont through the day with partly to mostly cloudy skies. 
Decreasing heights will likely push eastward to work in concert 
with high precipitable water (above the 90th percentile for the 
date) to cause more numerous showers with moderate to heavy 
rainfall to move through the whole North Country at times from 
Tuesday night through Wednesday. Again cannot rule out thunder 
during the daytime hours, but looks like limited instability 
will be available given little cooling aloft and relatively poor
surface heating. Highs will be a few degrees above normal where
there is ample sunshine on Tuesday, with otherwise near normal 
temperatures continuing through Thursday with some continued 
unsettled and humid weather. As of now, it looks like the
hottest period of this upcoming warm and humid stretch will be 
Friday to Saturday. On these days, heat index values could again
surpass 90 in most areas and surface based instability will 
likely support thunderstorms. With rising upper level heights 
expected, the threat for severe weather is low.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Through 06Z Monday...Mainly VFR through the TAF period with
clear skies and generally light winds expected. Expected
generally clear skies. Areas of patchy fog/low stratus are 
possible at KSLK, KMPV & KEFK after 08z. Anticipate periods of 
MVFR visibilities with VLIFR ceilings possible. Any reductions 
to visibilities/ceilings should lift by 12z with VFR through the
remainder of the period. Winds will between 5-10 kt from the 
W/NW becoming light and variable overnight. Tomorrow, winds will
remain generally 10 kt or less. 

Outlook...

Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. Isolated SHRA, Isolated TSRA.
Tuesday Night: Mainly VFR, with local MVFR possible. Chance SHRA,
Isolated TSRA.
Wednesday: Mainly MVFR, with areas VFR possible. Scattered SHRA,
Isolated TSRA.
Wednesday Night: Mainly MVFR, with areas VFR possible. Chance
SHRA.
Thursday: Mainly MVFR, with local VFR possible. Chance SHRA,
Chance TSRA.

&&

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

&&

$$
SYNOPSIS...Duell
NEAR TERM...Duell/LaRocca/Neiles
SHORT TERM...Kutikoff
LONG TERM...Kutikoff
AVIATION...LaRocca/Neiles