FXUS61 KBTV 250926
Area Forecast Discussion
National Weather Service Burlington VT
426 AM EST Sat Jan 25 2020
A complex weather system will bring wintry mixed precipitation
to the North Country this afternoon through Sunday. A Winter
Weather Advisory is in effect from 1 PM today to 4 AM Sunday
for portions of northern New York and Vermont. Ice accumulations
of a trace to two tenths are expected, with locally higher
along the spine of the Green Mountains. Locally gusty winds
upwards of 40 mph will also be possible this afternoon along
the western slopes of Green Mountains. Any mixed precipitation
will transition to rain or snow showers by Sunday afternoon.
Snow showers will linger through Tuesday morning with additional
accumulations of several inches likely. Quiet weather returns
by mid-week with seasonable conditions expected.
.NEAR TERM /THROUGH SUNDAY/...
As of 419 AM EST Saturday...Overall, no significant changes made to
the forecast with no substantial changes in 00z guidance suite.
Winter Weather Advisories remain in effect beginning 1PM today
through 4AM Sunday.
Current surface observations show highly variable temperature
readings across the area. Valleys across the Northeast Kingdom and
northern Adirondacks, as well as the northern Champlain Valley, have
fallen into the mid to upper teens overnight. More widespread
temperatures in the mid to upper 20s exist across much of Vermont
and the St Lawrence Valley of New York, while the western slopes and
higher terrain of the Adirondacks and Green Mountains currently
range from the upper 20s to upper 30s. These early reading
temperatures, along with cloud cover, have a real bearing on
expected warming today and thus precipitation type and impacts. Have
settled on a blend of the NAM/ECMWF using the top-down method, along
with high-res models for surface temperatures, all of which seem to
be capturing the current trends well. This largely lead to mainly
rain across the broader valleys, with a mix of freezing rain and
sleet for the Northeast Kingdom and northern St Lawrence Valley as
temperatures warm today into the low to upper 30s.
Radar imagery as of 345 AM shows precipitation slowly beginning to
spread eastward into central New York. Precipitation should begin to
overspread our far western areas of northern New York towards 18z,
before spreading to the east and north with everywhere seeing
precipitation by 01z. This shot of essentially warm air advection
precipitation will be rather quick as dry slot moves in by 09z.
Expect precipitation to taper off outside the confines of the higher
terrain & Northeast Kingdom with mainly dry weather during the first
part of Sunday. Colder air will begin to work its way back in
towards Sunday morning as upper level low moves overhead. Any
lingering mixed precipitation should transition to snow or rain
showers by Sunday afternoon.
QPF amounts are between 0.50-0.75", with locally lower amounts
between 0.25-0.30" due to downsloping along the western slopes of
the Adirondack and Green Mountains, as well as across the northern
CT River Valley (due to shadowing off the White Mountains). Although
a few ice jams exist along the St Regis and Winooski Rivers we are
not expecting any hydro concerns with this system. Snowfall totals
(including sleet) through Sunday evening are less than 0.50". Ice
accumulations between a trace and 0.20" are expected across the
Advisory area with locally higher amounts up to 0.40" along the
spine of the southern Green Mountains.
Lastly, the threat for gusty winds remain for portions of the
Adirondack and Green Mountains as 30-40 kt 925mb southeasterly jet up
across this area. Model soundings show best timing for mixing will
be between 15-20z before precipitation saturates and stabilizes the
low levels. Expect gusts between 30-40 mph for locations in western
Addison and Rutland counties, such as Bristol, Goshen, Brandon and
Rutland. Localized gusty winds will be likely across the Adirondacks
including Saranac Lake and Lake Placid. These values remain sub-
criteria, however very isolated power outages may be possible.
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 419 AM EST Saturday...Low pressure will pull away from the
region through the first part of next week, but a series of upper
shortwaves will rotate over the region. This with the continued
northwest flow will allow mountain snow showers to linger through
Tuesday. Mixed rain/snow showers will possible in the wider valleys,
particularly Sunday night and Monday. Additional snow accumulation
of a few inches will be possible during this time frame.
Temperatures will warm into the mid and upper 30s Monday afternoon,
but then turn slightly cooler on Tuesday with everyone near or below
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
As of 419 AM EST Saturday...Quiet weather prevails through the last
half of the week as high pressure settles across the region. This
also means it`ll trend a little colder, especially overnight when
mostly clear skies and light winds will allow for good radiational
cooling. Our next chance for precipitation arrives next weekend when
low pressure will move from the southern Appalachians northeastward.
Not a lot of agreement between the GFS and ECMWF on where this low
tracks, and a fair amount of spread in the GFS ensemble members as
well, so have stayed with just low chance PoPs for now.
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
Through 06Z Sunday...Mix of MVFR/VFR through the period with
wintry precipitation expected beginning Saturday afternoon.
Generally high clouds across the airspace, however maritime
airmass is moving into eastern Vermont where 1500-2500 ft
ceilings are being reported. Patchy freezing drizzle or fog may
be possible east of the Greens. Eventually all areas will see
MVFR ceilings/visibilities after 18z as deeper moisture moves
into the region. At the same time precipitation will also be
moving in, which will start as rain, with snow and/or freezing
rain mixing in, especially after 21z. The best chances for any
mixed precipitation will be at KMPV & KMSS. Increasing 925mb low
level jet approximately 30-40 kt will bring the threat for LLWS
at all TAF sites towards 20z. Winds be generally out of the
southeast around 10-15 kt. The exceptions will be at KRUT where
winds may gust as high as 30 kt at times Saturday afternoon and
KMSS where NE winds around 10 kt should hold on through the
Sunday: Mainly VFR, 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. Slight chance
Tuesday: Mainly MVFR, with local VFR possible. Slight chance
Tuesday Night: Mainly MVFR, with areas VFR possible. NO SIG WX.
Wednesday: VFR. NO SIG WX.
VT...Winter Weather Advisory from 1 PM this afternoon to 4 AM EST
Sunday for VTZ003-004-006>008-010-012-018-019.
NY...Winter Weather Advisory from 1 PM this afternoon to 4 AM EST
Sunday for NYZ026-027-030-031-034.