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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBTV 161426
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
1026 AM EDT Wed Aug 16 2017

.SYNOPSIS...
Dry weather is expected across the North Country today and
continuing into Thursday as high pressure builds moves down from
Canada. Cooler temperatures will exist today with highs in the
upper 60s to mid 70s...but temperatures quickly return to
seasonal normals both Thursday and Friday. A low pressure system
approaching the area on Friday will spread showers and a few
thunderstorms back into the region...especially Friday
afternoon and night.

&&

.NEAR TERM /UNTIL 11 PM THIS EVENING/...
-- Changed Discussion --
As of 1024 AM EDT Wednesday...Clouds clearing quickly in the
wake of the cold front with clear skies across northern areas
and some lingering, but thinning cloud cover to the south. Made
a few adjustments to sky cover to reflect trends but otherwise
previous forecast in excellent shape, no other changes.

As of 702 AM EDT Wednesday...Cold front has finally begun its
push southeast across the area. This combined with cold air
advection has helped to expand the areal coverage of clouds
across the area and these will likely persist through mid-
morning before clearing line...currently from Montreal to
Massena...works its way into the area. Have adjusted the
forecast to keep clouds in longer through the morning hours
before clearing takes place. Even indicated a few showers
through mid-morning over the Northeast Kingdom of Vermont based
on observations and radar. Otherwise rest of forecast in good
shape with some lingering fog over central and southern Vermont
for a couple more hours. Again should see more sun later this
morning and afternoon but cold air advection will keep highs in
the upper 60s to mid 70s across the area.

High pressure builds into the region tonight and we should see
clear skies and light winds for all areas. Any fog potential
will likely be confined to the favored locations as drier air
may win out overall. Should be the coldest night of the week
with lows in the mid 40s to mid 50s...but in the upper 30s at
Saranac Lake.
-- End Changed Discussion --

&&

.SHORT TERM /11 PM THIS EVENING THROUGH FRIDAY/...
As of 401 AM EDT Wednesday...High pressure remains over the
area on Thursday and this day has the makings of the best day of
the week. Should see plenty of sunshine...light winds...and
temperatures rebounding back into the 70s with a few 80 degree
readings in the larger valleys. Area remains in northwest flow
aloft Thursday night with ridge axis remaining to the west. This
should cause a delay to the precipitation that is associated
with an upstream trough of low pressure over the Upper Midwest.
Will therefore keep Thursday night dry and its not until Friday
afternoon for the upper ridge axis to move east of the area. Its
at this time that southwest flow aloft develops and spreads
moisture into the region. Have slowly increased precipitation
chances Friday morning and then bring better chances into the
region Friday afternoon. Highs on Friday will once again be in
the 70s to around 80.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 401 AM EDT Wednesday...Guidance continues the trend of
consistency between models of the last few days after being
worlds apart. The other consistency is the slower progression of
the northern plains system eastward as much of the energy is
rotating NNE across northern Great Lakes and Ontario but
eventually pushes east into and through FA.

By this forecast period (Friday night) the occluded front is pushing
into the CWA with the best lift/moisture moving across VT. By 12z
Sat the front is east of region but upper level trof is still back
across Great Lakes with several spokes of energy still to rotate
across the region. Timing and daytime heating/instability means
another threat of SHRA/TSRA Sat aftn/eve with the final upper level
trof passage during Sunday morning. There still may be enough
moisture and instability for some orographic showers Sunday.

Ridging at all levels approaches Sunday night and then slides
southeast by late Monday-Monday night. A rather nice late summer day
with highs above seasonable ...in the lower 80s.

Another trof digging into the Northern Mississippi River Valley
and Great Lakes (sound familiar) drops in on Tuesday with SW
flow at all levels behind the ridge and ahead of this system.
This shortwave/cold front appears more vigorous and its just a
matter of timing. Very Slight timing differences with Tue
ngt/Wed AM time frame. Moderate instability expected with temps
in L-M80s and 60s dewpoints and heights will be falling thus a
chance of thunderstorms late (esp in NY). Decent gradient looks
like enough shear that possibly strong to severe depending on
timing.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
Through 12Z Thursday...Cold front finally starting to make a
stronger push southward across the area. Winds will be
increasing from the north and northwest as a result with gusts
in the 10 to 15 knot range. The front is also producing a wide
range of ceilings...everything from VFR to IFR and these
conditions will continue through about mid-morning before
noticeably clearing moves down from Canada and ceilings go to
VFR everywhere for the remainder of the period after 16z. The
stronger winds have helped promote mixing and early morning fog
is all but gone.

Outlook...

Thursday: VFR. NO SIG WX.
Thursday Night: VFR. Chance SHRA.
Friday: VFR/MVFR. Likely SHRA...Slight Chance TSRA.
Friday Night: VFR/MVFR. Likely SHRA...Slight Chance TSRA.
Saturday: VFR. Chance SHRA.
Saturday Night: VFR. Slight Chance SHRA.
Sunday: VFR. Chance SHRA.

&&

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

&&

$$
SYNOPSIS...Evenson/Manning
NEAR TERM...Evenson
SHORT TERM...Evenson
LONG TERM...SLW
AVIATION...Evenson