FXUS61 KBTV 190753
Area Forecast Discussion
National Weather Service Burlington VT
253 AM EST Sun Jan 19 2020
A low pressure system will approach from the southwest this
evening and cross the North Country late tonight. This will
bring widespread accumulating snowfall over the region. The
heaviest snow will fall late this evening into the first part of
tonight, before tapering off through the day Sunday. Snowfall
amounts will be three to eight inches with locally higher
amounts across high terrain. Quieter weather and below normal
temperatures are expected for the first half of next week.
.NEAR TERM /THROUGH MONDAY/...
As of 1238 AM EST Sunday...Dry slot evident on satellite imagery
pushing in from the west over southern/central VT. Consequently,
seeing a defined back edge to the snow showers moving through
the southern half of our forecast area. Have adjusted PoPs to
reflect this, taking down PoPs especially over Rutland, Windsor,
Addison, and Orange Counties in VT. Further north, snow showers
will continue especially over higher terrain, but become lighter
in nature as we lose deeper moisture.
Previous Discussion: Surface low pressure has reached Lake
Huron as of 2345Z. In advance of this system, combination of
low-level WAA and deformation/frontogenesis is resulting in
widespread stratiform snowfall, with some embedded banding in
composite reflectivity. Best UVV generally between 02-07Z from
SW-NE, and still anticipate the snow to be moderate to heavy at
times during this period. Similarly, the 12Z HREF indicated
snowfall rates around 1"/hr through the next several hours,
which appears to align with the higher reflectivity values
upstream across central NY into the Adirondacks. Thus, much of
the accumulating snowfall will take place this evening through
about 06Z. The heavier snow lifts out of our area after 06-07z
tonight, with the surface low to traverse along the
International Border shortly thereafter. Temperatures will
likely rise slowly overnight on the aforementioned southwest
flow ahead of the low, especially in the St Lawrence Valley.
Once the low moves by, flow turns turns more to the west, with
colder air spilling in from west to east behind the departing
low. This more westerly flow will allow the widespread snow to
begin to become more focused in the mountains through the day
Sunday, with downsloping likely on the east side of the
Adirondacks to bring widespread snow to an end in the western
Champlain Valley. Overall expect a widespread 3 to 8 inches of
accumulation through Sunday afternoon, with locally higher
amounts likely in the higher terrain of the Adirondacks and
Green Mountains. Colder air begins to spill into the forecast
area from west to east Sunday behind the departing low, making
for quite a spread in expected high temperatures on Sunday,
ranging from around 20 in the St Lawrence Valley to the mid 30s
in more southern areas. Lapse rates steepen due to the cold air
advection as well, so expect we could see some gusty winds to
around 20 mph, which will result in areas of blowing snow. Any
snow lingering in the mountains Sunday night will wane overnight
as the best moisture shifts east with minimal additional
accumulation expected. It will be another cold night with lows
in the single digits in most spots.
.SHORT TERM /MONDAY NIGHT/...
As of 253 AM EST Sunday...Quiet weather is expected Monday
night into Tuesday with modified polar high pressure building
slowly east from the Great Lakes states. Did undercut national
blended guidance for low temperatures Monday night owing to
expected good radiative effects with values expected to bottom
out in the +/- single digits in the valleys and roughly 5 to 15
below in the mountains/Northeast Kingdom. Otherwise clear to
partly cloudy skies, light winds and near nil pops will be
offered. Highs on Tuesday to range from the teens in the
mountains and eastern VT to the lower 20s in the broader
Champlain and St. Lawrence Valleys.
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 253 AM EST Sunday...Tranquil weather then continues for
the remainder of the work week as aforementioned high builds
into and atop the region. A weak northern stream shortwave
passing off to our northeast may bring variable clouds and
perhaps a few northern mountain flurries Tuesday night,
otherwise dry weather is expected through Friday. Temperatures
gradually moderate over time as Pacific air becomes more
entrained into the northern tier of the lower 48 under zonal mid
to upper level flow. Given potential radiative cooling effects
at night diurnal temperature ranges will be slightly above
average. However, high temperatures should slowly climb through
the period, ranging from the upper 20s/lower 30s on Wednesday,
then 30s to locally near 40 for Thursday/Friday.
By next weekend signs that another system may affect the region but
inconsistency in timing among medium range solutions continues at
this time so only lower chance pops for rain/snow showers will be
offered at this point with highs in the 30s.
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
Through 06Z Monday...Variable conditions through the area with
predominantly MVFR/low VFR conditions further south and IFR/LIFR
conditions further north where snow showers will continue the
longest. The bulk of the snow at KRUT should be finished, with
improvement to VFR conditions expected and little more in the
way of accumulations. Snow will become lighter in nature at KBTV
and KMPV for the remainder of the night, with improvement to
primarily MVFR conditions expected. Further north and west, will
see continued LIFR/IFR conditions at KMSS, KSLK, and KPBG where
snow will continue the longest. Have included mention of LLWS
at most TAF sites at the beginning of the TAF period as
southwest jet remains overhead. In addition to LLWS, areas of
turbulence can be expected. Winds generally S-SE 10-15kt through
most of tonight. As low passes to our east, will see winds
becoming NW during the daylight hours on Sunday. Gusts up to
20kt will be possible late morning through Sunday afternoon, and
that may yield intervals of blowing snow.
Martin Luther King Jr Day: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Wednesday: Mainly VFR, with local MVFR possible. NO SIG WX.
Wednesday Night: VFR. NO SIG WX.
Thursday: VFR. NO SIG WX.
VT...Winter Weather Advisory until 4 PM EST this afternoon for
NY...Winter Weather Advisory until 4 PM EST this afternoon for