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Area forecast discussion
National Weather Service Burlington Vermont
1014 PM EDT Thu Jun 21 2018

high pressure will provide the region with clear skies and light
winds tonight with temperatures cooling into the 30s and 40s. Friday
will be dry with near normal temperatures, as high clouds increase
during the afternoon hours. Unsettled conditions with on and off
showers are expected this weekend with cool temperatures.


Near term /through Friday night/...
as of 1012 PM EDT Thursday...temperatures have been quick to
fall so far this evening. In fact, so quickly that our previous
forecast was lagging behind by about an hour. Went ahead and
adjusted temperatures to catch up with the current trends but it
looks like the min temp forecast still looks on point given the
current conditions. Based on what Saranac Lake has done thus
far, it wouldn't be surprising to see them touch 32 degrees
briefly before sunrise. Otherwise, current forecast remains well
on track with clear skies and high pressure reigning over the

Previous discussion...1018mb high pres over southern Canada
will provide cwa with light trrn driven winds tonight with
clear skies. These conditions will allow temps to quickly drop
after sunset with lows ranging from the l/M 30s slk/nek to
mid/upper 40s cpv. A few very isolated and patchy areas of frost
possible at slk and over the nek of Vermont early Friday morning.
Crossover values will be reached with several deeper/protected
valleys going 2 to 4 degrees lower. Some very light patchy fog
is possible eastern VT and isolated locations across northern New York
btwn 09-11z.

Mid/upper level ridge and associated sfc high pres slowly breaks
down as short wave energy and moisture approaches our cwa by
Saturday. Developing southerly flow on backside of sfc high pres
will aid in low level waa on Friday, with progged 850mb temps
climbing btwn 13c and 14c. These values combined with 925mb temps of
18 to 19c, will support highs in the mid 70s to lower 80s on Friday,
after a cool start. Expect a dry Friday night as high pres and deep
dry layer overhead delays the moisture arrival until Saturday.
However...weak embedded vorts in the flow aloft, along with
increasing 850 to 500mb rh will produce mid/upper level clouds.
These clouds combined with south/southeast winds will keep temps in
the mid 40s to upper 50s on Friday night.


Short term /Saturday through Sunday night/...
as of 313 PM EDT Thursday...a weakening vertically-stacked low
lifting out of the Ohio River valley will end our stretch of
sunny, dry weather this weekend. As the system tracks
northeastward from Ohio to western New York Saturday, the upper
low will become an open wave as it pushes a warm front
northward through the forecast area. An inverted trough along
the front will feed some Atlantic moisture westward into the
forecast area. The moisture transport into the area coupled with
broad, synoptic-scale ascent under the warm air advection
regime, will result in a cloudy and showery weekend for the
north country.

Timing the rain for the weekend proves a bit tricky, but the lack of
deep forcing as the system weakens over the area along with the
track of the low suggests on and off periods of light rain
developing Saturday morning over northern New York and spreading
northeastward through Saturday night. By Sunday morning, the
upper wave will have lifting northeastward out of the forecast
area, and many areas could see some breaks in the rain. However,
the clouds and generally unsettled weather will linger through
the day thanks to an advancing northern stream wave pushing in
from Canada. During the day Sunday, the rain will become more
widespread again as this wave approaches the international
border, providing more focused lift over the north country.

The persistent cloudiness will make for relatively uniform temperatures
through the weekend with highs in the mid 60s to low 70s
expected and lows in the 50s.


Long term /Monday through Thursday/...
as of 313 PM EDT Thursday...early Monday morning, a cold front
will push southward through the forecast area, clearing out
lingering moisture and bringing a return of sunny and dry
weather. Ridging will build over the northeastern US, and all
indications point to a very pleasant start to the next work
week. Temperatures will start out mild behind the frontal
passage; decreasing coverage of clouds through the afternoon
will lead to highs in the 70s for Monday. As the upstream upper
ridge shifts eastward by midweek, temperatures will warm 5-10
degrees each day, reaching the mid 80s by Wednesday. The next
chance for precipitation doesn't look to come until the
Thursday/Friday timeframe, when the next low will lift out of
the Midwest and spread some rain eastward.


Aviation /02z Friday through Tuesday/...
through 00z Saturday...VFR conditions will continue to prevail
through the forecast period as sky clear skies continue. A wind shift
from the north to south is expected between 13z and 15z in the
morning which will help usher in some moisture tomorrow
afternoon which may attribute to some cirrus beginning to move
overhead. Fog looks unlikely tonight as ample dry air remains
entrenched at the surface and we are now several days removed
from any significant rainfall.


Friday night: VFR. No sig weather.
Saturday: VFR. Chance rain showers.
Saturday night: mainly MVFR, with local IFR possible. Chance
rain showers.
Sunday: mainly MVFR, with local IFR possible. Likely rain showers.
Sunday night: mainly IFR, with areas MVFR possible. Chance rain showers.
Monday: mainly VFR, with local IFR possible. Slight chance rain showers.
Monday night: VFR. No sig weather.
Tuesday: VFR. No sig weather.


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



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