Area Forecast Discussion
Issued by NWS Burlington, VT
FXUS61 KBTV 220029
Area Forecast Discussion
National Weather Service Burlington VT
729 PM EST Sat Jan 21 2017
Cloudy yet unseasonably mild weather will continue for the
North Country this weekend. A weak disturbance will move
northeastward into prevailing high pressure, and provide just a
chance of patchy drizzle today into tonight. The start of the
work week brings a more active period of weather. A moisture
laden system moving slowly northeastward from the Gulf coast
states will bring a wintry mix to the North Country, along with
the potential for strong and gusty winds, especially along the
western slopes of the Green Mountains. After this system shifts
away through the Canadian Maritimes, temperatures will remain
unseasonably mild. Additional rain or snow showers are possible
through the latter half of the week.
.NEAR TERM /THROUGH SUNDAY/...
As of 716 PM EST Saturday...Forecast for the rest of the
evening tracking along well as temperatures slowly begin to fall
into the upper 30s. Still see a few sites reporting lowered
visibilities unusually high dew points in the mid to upper 30s
as well. Think the idea of some patch fog continuing especially
over northern New York.
High pressure at the surface and aloft through 500 mb will
continue through the near term period, although the surface
ridge shifts east to the Gulf of Main coast while upper ridge
flattens in advance of approaching trough. Plenty of moisture
locked near the surface below 850 mb, and while some webcams are
showing breaks in the overcast expect skies to remain
predominantly overcast through the near term period. Despite the
cloud cover temperatures will remain mild and show little
diurnal change. Overnight lows in the 30s limited by cloud cover
and dewpoints in the low 30s, while max temps Sunday similar to
today in the upper 30s to low 40s. Patchy light fog will
redevelop tonight in moisture laden boundary layer.
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
As of 345 PM EST Saturday...A weak upper level ridge will be
cresting overhead on Sunday evening however a shortwave surface
trough will be sliding through at the surface so we will likely
see some light snow flurries/drizzle across the North Country
mainly in the higher terrain. With a low level inversion in
place due to the subsidence from the upper level ridge expect
overcast skies through the evening and into Monday morning.
By Monday the upper level ridge begins to break down as a closed
500mb low tracks up through the Carolinas into the Mid Atlantic
region. As the corresponding surface low tracks up the northern
Mississippi Valley region our synoptic winds will develop a
strong easterly component. We will also see continued moisture
advection from the south and east but with the lack of forcing I
dont anticipate much precip to begin falling until late Monday
and into Monday evening. Precip type still looks to be a mixed
bag of sorts but the generally idea is that we will see some
sort of snow/sleet/rain mixture so continue to prepare for slick
and slippery conditions Monday evening.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
As of 356 PM EST Saturday...By Monday evening the energy from
the surface low dives offshore and low then continues to track
just off the coastline. The latest 12z suite of guidance brings
the low just inside of the benchmark and thermal profiles again
suggest we will continued the sleet/snow mixture. The GFS is a
bit warmer with the EC depicting more of a snow solution. With
the variations in the track of the surface low over the past
several runs confidence is on the lower side of exact track.
Unfortunately with the way the boundary layer temps are with
this low that track detail will be critical for the North
Country in determining the precip type. So for the time being
I`ve continued to opt towards using a blended thickness approach
to create the weather grids. The big take away precip wise is
that we are expected a prolonged period of wintry mix to impact
the North Country beginning late Monday night and finally
pushing North and east out of the area by Wednesday morning.
The more significant impacts are expected to the the potential
for strong easterly downsloping winds. With the track of the
surface low oriented due south of the region expect strong
easterly winds to track across the southern Greens. Expect winds
in the 20-30 mph range with gusts of 35-45mph possible. The
strongest winds will be located on the western slopes of the
southern Greens and generally within a few miles of the
ridgelines. With the moderate precip and overcast skies we may
not mix the strongest winds down but that will be something to
keep and eye on moving forward.
The pattern remains active behind that phased system as the
guidance brings another low pressure system from the Great Lakes
in the Wednesday night/Thursday time frame but right now that
system looks cold enough to be mainly snow. The region will
stay remain under cyclonic flow on Friday with continued chances
of rain or snow showers.
.AVIATION /00Z Sunday THROUGH Thursday/...
Through 00Z Monday...Low level moisture trapped beneath
inversion layer will maintain MVFR/IFR ceilings through the next
24hrs with HIR TRRN OBSCD. The inversion doesn`t look likely to
break so the low level stratus will persist through the TAF
period with patchy fog across the northern New York sites.
Expect MVFR ceilings at all sites except IFR at SLK/MSS.
Visibilities will be reduced to MVFR at MSS/PBG/SLK with periods
of IFR possible. Expect that to improve to MVFR/VFR after 16z
Outlook 00Z Monday through Thursday...
18z Sunday - 18z Monday...MVFR to IFR ceilings and visibility
Sunday night and Monday improve to VFR for a short time Monday.
18z Monday through Thursday...Conditions deteriorate to IFR
with widespread wintry mix of precipitation moving in late
Monday into Tuesday, then temperatures cooling to support snow
through Thursday. Strong southeast downslope winds on
Monday...especially at KRUT, with gusts in excess of 25kts
possible. Brief period of improving conditions possible early
Wednesday, before occasional SW renews. Thursday area coverage
of showers becomes more patchy through Thursday.