FXUS61 KBTV 242029
Area Forecast Discussion
National Weather Service Burlington VT
329 PM EST Fri Jan 24 2020
A low pressure system will bring messy weather to the North Country
over the weekend with a mix of wintry precipitation. A Winter
Weather Advisory is in effect 1PM Saturday to 4AM Sunday due to
light ice accumulations, which may impact travel. Temperatures will
cool following the departure of the low, leaving mountain snow
showers in it wake throughout the beginning of the week. Showers
will cease Wednesday and quiet weather is in store for the remainder
of the week.
.NEAR TERM /THROUGH SATURDAY/...
As of 327 PM EST Friday...Currently, surface high pressure is
situated off the coast of New Brunswick and departing eastward.
Meanwhile, a vertically stacked low pressure system is approaching
from the southwest. This will induce easterly flow at the surface,
allowing low level moisture to be trapped along the east side of the
Greens and channeled down the St. Lawrence Valley. Consequently, low
clouds will develop within these regions, and patchy freezing
drizzle is likely during the overnight hours despite being dry
aloft. Thus, roads may be slick at times. The additional cloud cover
will keep overnight low temperatures moderate across southeastern VT
(upper 20s), while elsewhere lows will be in the low 20s.
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
As of 327 PM EST Friday...A Winter Weather Advisory has been issued
beginning 1PM Saturday and continuing until 4AM Sunday for the
northern Saint Lawrence Valley, eastern Adirondacks, and central &
eastern VT due to mixed precipitation and light ice accumulation.
As the low pressure system draws near Saturday, winds will increase,
becoming southeasterly. Highs will reach mid to upper 30s under warm
air advection before the precip sets in. Model guidance is in good
agreement regarding the arrival of precip, beginning in
northern NY during the early afternoon and reaching VT by early
evening. Precip will be heaviest within the first few hours of
the onset; during this time, there is favorable synoptic ascent
paired with mid-level f-gen, low level convergence, and a strong
low level jet of 50-60kts out of the southeast. This will cause
breezy winds at the surface with gusts up to 25-35kts,
particularly along the western slopes of the Greens and
Adirondacks. In addition, areas northwest of higher terrain,
namely the Champlain Valley, portions of northern NY, and the
Northeast Kingdom, may see lesser precip due shadowing of the
One of the main challenges with this system continues to be the
precipitation type. Thermal profiles are within a degree or two of
freezing at the surface and all the way up to 800mb; thus, a slight
change in the temp profiles, whether at the surface or aloft, could
significantly alter the p-type. As the forecast stands, precip will
begin as rain, with freezing rain/sleet or snow more likely across
higher elevations (>2000ft). This will continue overnight until
temperatures begin to cool aloft Sunday morning as the low lifts
northeastward. During this time, chances for precip will dwindle and
transition into a light snow/sleet mix. Winds will become
southwesterly, favoring mountain snow showers for Sunday afternoon.
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
As of 327 PM EST Friday...The extended forecast will return to
relative calm. Temperatures on Wednesday could actually be near
normal. We stick with northwest flow, but without significant Arctic
air. Monday and Tuesday, low- level moisture will be lingering over
the area with weak mid to upper level perturbations keeping that
chance for snow showers. These would mainly be over the mountains.
Dry air begins advecting into the North Country on Wednesday and
winds turn westerly as a shortwave ridge moves into place. This will
dry things out completely mid-week, and we should trend a bit warmer
into the weekend.
Ensemble forecasts and deterministic solutions are in good agreement
of the 500mb height pattern. Thus, it appears quite likely a system
comes through toward the end of next weekend. There`s a northern
stream shortwave and then a stronger southern stream shortwave. What
happens with these will affect how things play out near the surface.
At this stage, it is way too early to expect model consensus, and
not surprisingly, there is none.
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
Through 18Z Saturday...VFR conditions will continue through the
first part of the TAF period with light and variable winds
tonight, trending southerly beyond 06Z Saturday. Lower ceilings
will be possible after 00z as recycled maritime air advects
into the region, with the greatest chance of a BKN deck around
2000ft agl at KMPV. Patchy -DZ or -FZDZ possible mainly at KMPV,
but could impact KMSS as well. This could bring reduced
visibilities down to 4SM-6SM. Patchy drizzle lifts around 12Z as
next system approaches. Wind speeds increase to 5 to 10 knots
with higher sustained winds and gusts at KRUT. Some LLWS will be
possible at KSLK after 15Z and currently forecast WS020/16035KT.
Precipitation should hold off to 18Z Saturday.
Saturday Night: Mainly MVFR, with local IFR possible. Definite
RA, Definite FZRA.
Sunday: Mainly MVFR, with local IFR possible. Chance SHRA, Chance
Sunday Night: Mainly MVFR, with local IFR possible. Chance SHSN.
Monday: Mainly MVFR, with local IFR possible. Chance SHSN.
Monday Night: Mainly MVFR, with local IFR possible. NO SIG WX.
Tuesday: Mainly MVFR, with local IFR possible. NO SIG WX.
Tuesday Night: Mainly MVFR, with local VFR possible. NO SIG WX.
Wednesday: Mainly VFR, with areas MVFR possible. NO SIG WX.
VT...Winter Weather Advisory from 1 PM Saturday to 4 AM EST Sunday
NY...Winter Weather Advisory from 1 PM Saturday to 4 AM EST Sunday