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fxus61 kbtv 200734 

Area forecast discussion
National Weather Service Burlington Vermont
334 am EDT Wed Jun 20 2018

a cold front dropping southward out of Canada will bring a chance of
showers to northern areas this evening through midnight, with high
pressure returning for Thursday and Friday. Unsettled conditions are
expected for the weekend with periods of rain likely, along with the
chance for a few rumbles of thunder.


Near term /through Thursday/...
as of 333 am EDT Wednesday...main weather feature of interest
for the next 36 hours will be a cold front dropping southward
from Canada this evening through the overnight hours. Ahead of
the front, mostly sunny and dry conditions are expected for
today with temperatures about 5-10 degrees warmer than yesterday
in the mid 70s to low 80s. Cold front approaches the
international border around sunset with the latest 00z cam
models indicating a little more instability and forcing compared
to previous runs so have bumped up pops into the 30-50% range
across northern areas through midnight. Instability is only on
order of a couple hundred j/kg of cape through about 02z so
included just a slight chance of thunder along the border
through that time. Otherwise, convective activity fizzles as it
moves south after sunset so central and southern areas will
likely remain dry. There will be a marked increase in sky cover
with the frontal passage which will help to keep overnight temps
milder than the previous night in the mid 40s to mid 50s.

For Thursday, high pressure returns behind the departing front
with northerly flow in the low/mid levels keeping temps on the
cool side back in the upper 60s to low 70s despite full


Short term /Thursday night through Friday night/...
as of 333 am EDT Wednesday...the Thursday night thru Friday
night period will feature generally tranquil weather as sfc high
pressure builds from sern Ontario/swrn Quebec esewd across
northern New England, and eventually into the Canadian Maritimes
by Friday aftn into Friday night. Should see good radiational
cooling conditions with light winds and clear skies Thursday
night. Lows generally mid-upr 40s, but would anticipate some upr
30s in the normally colder locations within the nrn Adirondack
region and across sheltered locations of far nern Vermont. Should see
a moderating air mass on Friday as south winds develop around
10 mph. Relatively low humidity levels (2-M dewpoints in the upr
40s to lower 50s) will continue, but high temperatures will be
warmer on Friday, reaching the upr 70s to lower 80s. Will begin
to see some fringe effects of closed 700-500mb low expected
across the Ohio Valley Friday night. As this system slowly
shifts newd, increasing cloudiness is expected Friday night. The
00z European model (ecmwf) suggests associated precipitation remains south and
west of our region Friday night, but the 00z GFS is a bit
quicker to bring potential rain showers into nrn New York after
midnight. At this point, indicated just 20-30 pops for Franklin
New York and St. Lawrence counties during the pre-dawn period
Saturday. The increasing cloud cover will result in milder
overnight temperatures, with pre-dawn lows mainly in the 50s,
except near 60f for the St. Lawrence Valley.


Long term /Saturday through Tuesday/...
as of 333 am EDT Wednesday...both the 00z European model (ecmwf)/GFS suggest
unsettled weather this weekend as mid- level low over the Ohio
Valley is forecast to become an open wave and lift newd across
New York state on Saturday, and eventually across nrn New England for
Saturday night. A second mid-level trough in nwly flow moves
across the north country late Sunday into early Monday, with the
potential for additional scattered showers. Precipitable water
values will be moderately high but not excessive. Unlike the 2"+
precipitable water experienced this past Monday, will see values 1.5-1.7" in
advance of the Ohio Valley system for Saturday. Overall, present
indications suggest cloudiness and weak mid-level lapse rates
will keep instability low (sbcape < 1000 j/kg). Anticipate
widespread showers Saturday, and included a chance of embedded
thunderstorms west of the green mtns, including the Champlain
Valley and all of nrn New York (slight chance tstm east of the green
mtns). Severe storms not currently expected. Highs on Saturday
mainly in the 70s. Maintained 60-80 pops for Saturday night with
lows in the upr 50s to lower 60s. May see a break in the shower
activity on Sunday - especially during the morning hrs - but
with trailing shortwave trough approaching from sern Ontario,
should see another period of widespread showers late Sunday into
Sunday night/early Monday. Gradual clearing is anticipated
Monday night into Tuesday. Highs on Monday only in the lower
70s, but increased prospects for sunshine should result in highs
in the 75-80f range for valley locations on Tuesday.


Aviation /08z Wednesday through Sunday/...
through 06z Thursday...outside of some patchy IFR fog at kmpv
and kslk overnight, conditions will be largely VFR through the
period. Overnight sky clear will trend towards a few cirrus and fair
weather cumulus this afternoon before a low/mid level deck
increases from the north late afternoon Onward as a cold front
approaches. Could see a few showers along the international
border to the Adirondacks and central Vermont from sunset through
midnight, with brief reductions in vsby possible.


Thursday: VFR. No sig weather.
Thursday night: VFR. No sig weather.
Friday: VFR. No sig weather.
Friday night: VFR. No sig weather.
Saturday: VFR. Chance rain showers.
Saturday night: MVFR/IFR conditions possible. Chance rain showers.
Sunday: mainly MVFR, with areas IFR possible. Likely rain showers.


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



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