FXUS61 KBTV 201141
Area Forecast Discussion
National Weather Service Burlington VT
741 AM EDT Sun Aug 20 2017
Clouds will continue to decrease in areal coverage this morning
with a good deal of sunshine expected for this afternoon. 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 740 AM EDT Sunday...Overall forecast in good shape. Have
been able to remove mention of showers as upper trough axis
finally east and isolated showers over northern Vermont have
moved east of the area or dissipated. Some fog did develop over
southeast Vermont and have added it to the forecast for the next
couple of hours until the winds shift to the west and better
mixing occurs. Have also adjusted sky cover trends as clouds are
breaking up rather quickly. Rest of forecast in good shape and
no other changes needed at this time.
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/...
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
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
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.
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Through 12Z Monday...Upper trough has finally moved out of the
area and isolated showers have dissipated or moved east of the
area. Drier air is moving in from the west and northwest as high
pressure builds into the region. This is helping to erode the
clouds over the area and thus any VFR/MVFR ceilings will only
linger through about 15z before VFR conditions develop for the
remainder of the period with little in the way of any cloud
cover. Winds will be from the west and northwest at 5 to 15
knots through about 00z and then as high pressure settles over
the region after 00z...winds will become light and variable.
Monday: VFR. NO SIG WX.
Monday Night: VFR. Slight Chance SHRA.
Tuesday: VFR. Breezy. Chance SHRA...Slight Chance TSRA.
Tuesday Night: VFR/MVFR. Likely SHRA.
Wednesday: VFR. Slight Chance SHRA.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.