Area Forecast Discussion
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FXUS61 KBTV 171940
Area Forecast Discussion
National Weather Service Burlington VT
240 PM EST Fri Feb 17 2017
High pressure building eastward across the North Country will
bring cold temperatures and dry weather overnight, with just
passing mid to upper level cloudiness. As the high pressure
system shifts to our east, a warm front will approach with winds
shifting into the south and southwest on Saturday. Temperatures
will moderate considerably, with valley high temperatures in
the upper 30s to lower 40s over the weekend. Also, a weak upper
level disturbance will bring increasing clouds, with a slight
chance for light rain or snow showers, mainly Saturday night
into Sunday. Temperatures generally above seasonal levels and
relatively dry weather conditions are expected during the work
week next week.
.NEAR TERM /THROUGH SATURDAY NIGHT/...
As of 1243 PM EST Friday...Visible satellite imagery showing
continued clearing trend across the region, with most locations
mostly clear at 1745Z. Low-level subsidence will increase as sfc
ridge axis across wrn PA/NY, Lake Ontario, and sern Ontario
gradually build ewd into nrn NY this afternoon, and across VT
tonight. Should see high pressure shift east of VT toward
daybreak on Saturday. Winds will continue W-NW around 10kts thru
sunset, and then become light SE-S after midnight as ridge axis
shifts to the east of the region. We should have excellent
radiative cooling for a time this evening through about 6Z,
especially given deep snow pack in many areas. 12Z NAM model
soundings suggest some increasing mid to upr level clouds from
west to east after midnight...and along with developing light
south winds, will probably see temps rise a bit during the pre-
dawn hrs from the Champlain Valley wwd. Longer period of clear
skies and decoupled PBL east of the Greens suggest trending
toward colder GFS-MOS for ern portion of VT. Overall, looking at
overnight lows in the low-mid teens, but single digits expected
across the normally colder spots in the nrn Adirondacks and
across ern VT.
On Saturday, we`ll see relatively strong 850-700mb WAA as low-
level flow becomes swly, and surface winds in the Champlain and
St. Lawrence Valleys increase to 10-20 mph. Valley highs
generally expected in the upr 30s to lower 40s. It appears a
weak nrn stream shortwave will bring the chance for a few
sprinkles/mtn snow showers during Saturday night. Highest PoPs
are across the nrn mtns, with PoPs generally 30-50 percent with
just a few hundreths of an inch of liquid equivalent forecast.
Lows Saturday night generally expected in the low-mid 30s under
mostly cloudy skies, except upper 20s above 1000-1500ft
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
As of 239 PM EST Friday...Latter half of the weekend turns
briefly unsettled as a weak clipper system and shortwave energy
passing north across southern Ontario/Quebec will renew chances
for some light shower activity, though with weak forcing and an
overall lack of deep moisture expect the highest chances to be
across the higher terrain and scattered at best. Temperatures
remain rather mild with highs in the mid 30s to low 40s and lows
in the 20s, which will produce a mix of rain/snow in any
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 239 PM EST Friday...Next week begins with surface high
pressure settling in over central Quebec along with an upper
ridge building in from the Great Lakes. Northerly flow around
the high will bring temps back down to more seasonal levels with
highs mainly in the low/mid 30s, and the combination of clear
skies and deep snowpack leading to good radiational cooling
Monday night with lows in the single digits to teens. Upper
ridge and surface high center over the region on Tuesday with
temps warming back above normal as south/southwesterly flow
increases ahead of our next system which looks to bring another
quick round of rain and snow showers Tuesday night through
Wednesday. Fast westerly flow ensues for Thursday with some weak
terrain driven showers possible, before the pattern becomes
highly amplified Friday ahead of a potential big system for next
weekend. If the GFS/ECMWF solutions pan out we could be looking
at very warm temperatures and an abundance of rain which could
lead to rapid snowmelt and potential flooding problems. Stay
.AVIATION /20Z Friday THROUGH Wednesday/...
Through 18z Saturday...VFR conditions during the period with
just passing mid-upr level clouds. NW winds 5-10kts will
diminish toward sunset with high pressure building in from the
west. Winds will shift light SE toward daybreak, and then S-SW
during the daylight hours on Saturday, approaching 10kts by 18Z.
Outlook 18z Saturday through Wednesday...
It appears areas of MVFR ceilings will return later in the day
Saturday with SW winds bringing in lake induced cloudiness
associated with moisture from the ern Great Lakes. Will see
periods of HIR TRRN OBSCD 18Z Saturday through 12Z Monday.
Any precipitation will be light, mainly isold/sct light rain or
snow showers during Saturday night into early Sunday.
Significant precipitation is not expected during the outlook