-- Discussion containing changed information from previous version are highlighted. --
105
FXUS61 KBTV 200901
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
501 AM EDT Sun Aug 20 2017

.SYNOPSIS...
We will see clouds and some lingering showers over the area
early this morning...but drier air will begin to move in and
increasing amounts are expected as the day wears on. High
temperatures will be in the mid 70s to lower 80s. Dry weather
continues tonight and Monday as high pressure moves across the
area. A warming trend will take place with highs in the 80s and
a good deal of sunshine. Above normal temperatures continue on
Tuesday with highs in the 80s...but an approaching trough of low
pressure will enhance the potential for showers and
thunderstorms Tuesday afternoon and night.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 426 AM EDT Sunday...Water vapor imagery shows well
defined trough over Quebec Province early this morning which is
enhancing rain showers over northeast New York and northwest
Vermont. These showers will continue through about 12z...which
is when trough axis finally shift east of the area. Noticeable
drying is taking place upstream across southeast Ontario and
thus we should be able to see increasing amounts of sunshine as
the day wears on. Highs will be in the mid 70s to lower 80s.

For tonight and Monday...high pressure builds in tonight and
gradually exits the area on Monday. Dry weather is expected
during this time period with little in the way of cloud cover as
well. Flow in the low and mid levels becomes west and
southwest...which will allow for warm air advection to take
place. Based on increasing 850 mb temperatures all areas should
easily get into 80s with a few spots in the Champlain Valley
getting into the upper 80s. Solar eclipse viewing on Monday
still looks good with little in the way of cloud cover.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
-- Changed Discussion --
As of 455 AM EDT Sunday...Monday night should mainly remain dry
ahead of approaching frontal system which will bring showers
and thunderstorms to the area later Tuesday and Tuesday night.
Warm air advection continues on warm southwesterly flow,
temperatures will only drop into the 60s across the North
Country. Could see a couple isolated showers in the Saint
Lawrence valley. On Tuesday, a low pressure system will move
Northeastward from the Northern Great Lakes into Southern
Quebec. Warm air advection on moist southwesterly flow continues
on Tuesday and max temps will edge into the upper 80s, with
perhaps a couple 90 degree readings in the warmer spots. Looks
like surface cold front will still be west of our forecast area
by 00z Wed. Think that by Tuesday afternoon we could have some
surface based instability, especially in the Saint Lawrence
valley and Northern Adirondacks, enough for some thunderstorms
to pop up ahead of the approaching cold front. Have increased
pops after 18z in our western zones to likely. Pretty strong
upper level jet dynamics, so think that storms that do form
could have strong gusty winds and heavy rainfall with pwats
nearing two inches by Thursday evening. Have not added enhanced
wording yet, but may need to as we get closer to Tuesday
afternoon.
-- End Changed Discussion --

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
-- Changed Discussion --
As of 500 AM EDT Sunday...Surface cold front will push west to
east across our forecast area Tuesday night, widespread showers
and isolated thunderstorms are expected. As previously
mentioned, gusty winds and heavy rain will still be possible
with high pwats and favorable jet dynamics. Not the best time
for a fropa in regards to severe weather, but at this time looks
like some of the storms could be strong. We may have some
showers Wednesday and Wednesday night with upper level trough
trailing departing surface frontal system crossing our forecast
area. Conditions will trend drier from Thursday onward with
large ridge of surface high pressure building into the region
from the North for most of the period.
-- End Changed Discussion --

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
Through 06Z Monday...An upper level trough is moving across the
area early this morning and will be east of our area by 12z.
Expect VFR to MVFR ceilings through 12z before VFR conditions
are expected for the remainder of the period as little in the
way of cloud cover is expected. Winds will pick up from the west
and northwest this morning at speeds in the 5 to 15 knot range
before tapering off after 00z tonight.

Outlook...

Monday: VFR. Breezy. NO SIG WX.
Monday Night: VFR. Slight Chance SHRA.
Tuesday: VFR. Breezy. Chance SHRA...Slight Chance TSRA.
Tuesday Night: VFR/MVFR. Occasional SHRA...Slight Chance TSRA.
Wednesday: VFR. Chance SHRA.
Wednesday Night: VFR. Slight Chance SHRA.
Thursday: VFR. Slight Chance SHRA.

&&

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

&&

$$
SYNOPSIS...Evenson
NEAR TERM...Evenson
SHORT TERM...Neiles
LONG TERM...Neiles
AVIATION...Evenson