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Area forecast discussion 
National Weather Service Burlington Vermont
310 PM EDT Tue Sep 27 2016

nearly stationary upper level low pressure over Lake Superior will
continue to bring dry and seasonally warm conditions to the north
country through Wednesday. Chances for showers increase for the
end of the work week and into the weekend though as the low drifts
southward into the Ohio River valley on Thursday, remaining there
through Saturday.


Near term /through Wednesday/...
as of 225 PM EDT's turned out to be yet another
gorgeous early fall day across the north country as an occluded
front has shifted east of the region this morning leaving US
underneath a mid-level dry slot. Partly sunny skies have ruled,
along with temperatures climbing into the mid 60s to low 70s.
Dewpoints have lowered to very comfortable levels as well,
generally in the 40s. We have seen a few isolated showers though
move through the St. Lawrence and northern Champlain valleys, but
that activity has since dissipated or is dissipating so a quiet
and comfortable afternoon will persist into this evening.

For tonight into Wednesday, a semi-stationary closed upper low
over Lake Superior will continue to be the dominating weather
feature across the Great Lakes and into the northeast as it very
slowly meanders south. Mean south/southwesterly flow in a dry
slot aloft will continue to rule over the area which will keep
conditions dry with variable cloudiness. It will also keep US on
the mild side of normal in regards to temperatures with tonights
lows only dropping down into 40s for most, exception being the
colder hollows of the Adirondacks where some upper 30s are
possible. Highs tomorrow will be similar to today for locations
west of the Green Mountains in the mid 60s to low 70s, but east of
The Spine it'll be a little cooler as a low marine stratus layer
moves in overnight and continue through the first half of
Wednesday. If the stratus deck wasn't there tonight, fog would be
a good bet for all of our climo favored river valleys, but as such
I think it will be confined to northern New York where skies will
be clearest and winds light.


Short term /Wednesday night through Thursday night/...
as of 310 PM EDT Tuesday...ridging aloft will help keep bulk of
precip associated with large 500mb closed low over the western
Ohio Valley as models show 500mb hts increase through Thursday
evening. At the surface, large ridge over the eastern half of
Canada reinforces lack of movement of weak surface low around the
Ohio Valley. Expect cloudy conditions across southern half of the
forecast area and partly cloudy for areas north to start the
period, but as flow at 850mb and 925mb becomes more easterly late
Thursday, low level moisture and clouds will spread across
northern areas as well. Chances for rain showers will be closest
to the aforementioned low, therefore, Adirondacks and south
central Vermont will see chances for rain, while most other areas
expect dry or only slight chance. Thursday night will see the
closed 500mb low eventually start to migrate northward.


Long term /Friday through Monday/...
as of 310 PM EDT Tuesday...the closed mid/upper level low
pressure looks to slowly travel northward, bringing increasing
chances for precipitation across the north country. On Saturday
this low picks up momentum with the highest chances for rain
showers affecting the area Saturday night through most of Monday
as a occluded front moves from SW to NE. As the mid-upper low
moves over the eastern Great Lakes region, it will weaken,
especially as it begins to move into New York on Monday. Models vary on
track at this point. Not a strong or deep moisture feed associated
with this system, as warm conveyor belt associated with coastal
low. Therefore, not expecting heavy precip as pwats stay within 1
Standard deviation of normal across the north country.


Aviation /19z Tuesday through Sunday/...
through 18z Wednesday...mainly VFR conditions are expected through
the period with a few tricky exceptions. Scattered VFR clouds
across the area this afternoon will generally dissipate going into
the evening hours, but overnight MVFR and vlifr are likely at kmpv
and kslk. For kmpv, a developing marine stratus layer off the
Maine coast will make a run into portions of eastern Vermont
towards dawn Wednesday, mainly affecting terminals east of The
Greens. Meanwhile at kslk, clearer skies, light winds and recent
rainfall will make for the high likelihood of dense fog as early
as 03z, and lasting through at least 12z. After 12z, kslk fog
Burns off, but timing of the stratus deck lifting at kmpv is a bit
more uncertain. Have gone with 16z there, but could see it
lasting longer. Final aviation challenge will be increasing
southeasterly flow at krut, where expect gusts 20-25kts to begin
early Wednesday morning and likely last through the day.

Outlook 18z Wednesday through Sunday...

18z Wed - 00z Fri: mainly VFR.

00z Thu - 00z Mon: mainly VFR with MVFR in rain showers possible,
especially on Saturday/Sunday.


Btv watches/warnings/advisories...
New York...none.


near term...lahiff
short term...kgm
long term...kgm

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