FXUS61 KBTV 230522
AREA FORECAST DISCUSSION
National Weather Service Burlington VT
1222 AM EST Wed Jan 23 2019
Temperatures will drop back into the single digits across much of
the region this evening. Then clouds and brisk southerly winds
develop overnight as temperatures warm into the mid teens to lower
20s by Wednesday morning. A period of light snow will develop early
Wednesday, which will change to a light wintry mix by evening with
some locations experiencing a cold rain. A cold front will produce
another period of rain changing to snow on Thursday, with some snow
accumulation likely. Colder temperatures with scattered snow showers
return for Friday into the weekend.
.NEAR TERM /UNTIL 1 PM THIS AFTERNOON/...
As of 351 PM EST Tuesday...A complex scenario setting up through the
near term period as we'll see a wintry mix event playing out. High
pressure currently cresting over the region will move east this
evening, allowing warm air advection to take place as the flow turns
to the southwest. Already seeing high clouds spreading across the
area this afternoon, and this trend will continue through the
evening hours. Low temperatures will occur early this evening, then
anticipate temperatures will slowly rise overnight as low-level warm
air advection takes place on a 50+kt 850-900 mb jet. Precipitation
associated with this warm air advection will begin to spread into
the western fringes of our forecast area, in the form of light snow.
Things start to really become complicated Wednesday and Wednesday
night as the warm air advection continues. The recent bitterly cold
air will be difficult to scour out, so anticipate snow will mix with
sleet and freezing rain as it spreads eastward through the day.
Areas like the Champlain Valley and southern St Lawrence Valley will
warm above freezing first, by early afternoon or so, but along and
east of the Greens, temperatures will remain below freezing through
the day and into the evening hours. However, surfaces like roads
will likely still be very cold, owing to the recent spate of bitter
cold, and icing will still be possible even once temperatures rise
above freezing. Snow and ice accumulations will be relatively minor;
1-3 inches and up to a tenth of an inch, respectively. However,
anticipate travel will be impacted due to packed snow already on
roads and the aforementioned cold surface temperatures. Have
therefore issued a Winter Weather Advisory for the entire area from
early Wednesday morning through Wednesday evening.
The other concern for this period will be gusty south winds due to
the low-level jet. Gusts up to 35 mph will be possible, especially
in the Champlain Valley.
.SHORT TERM /1 PM THIS AFTERNOON THROUGH THURSDAY NIGHT/...
As of 347 PM EST Tuesday...Thursday will begin with a surface
low quickly shifting northeast into the Quebec Province as
secondary low pressure development occurs just east of the
Appalachian mountain range. Thus, precipitation chances will
continue into Thursday before decreasing as the system moves
east on Thursday evening. The break will be short-lived, as
another feature begins to shift east heading into Friday
A strong 170-180kt jet streak will shift northeast Thursday, with
the North Country near the right entrance region. Cyclonic vorticity
advection from a 500mb shortwave rounding the base of longwave
trough will be favorable for precipitation. Good frontogenetic
forcing will also be present with good low to mid-level deformation
in place, mainly across Vermont. Heaviest precipitation will focus
itself along these features before shifting east by Thursday
afternoon. Temperatures will start in the 30s with cold air
advection gradually lowering temperatures from west to east during
the day. Thermal profiles indicate a quick transition to snow as
boundary layer temperatures approach the freezing point and
allow the rain-snow line to gradually shift east throughout the
day. About a tenth to a half inch of precipitation is expected
with the greater amounts along eastern Vermont. Snow across
lower elevations will generally be a dusting to 2" with higher
elevations seeing 2-4". Lows for Thursday night will be in the
.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 347 PM EST Tuesday...An active weather pattern is
expected to continue during the long-term. Our region will be
under the influence of a strong longwave trough across our area
with several with several smaller scale features embedded within
the cyclonic flow. The first of many will move through Friday
morning. Surface low associated with the shortwave will send a
strong cold front across the region. Modest instability is
present with mixed layer extending up to roughly 700mb. Snow
showers look like a good possibility, mainly along southern St.
Lawrence County, which will benefit from moisture advecting from
Lake Ontario. Temperatures will fall below average behind this
front, though chances for snow showers will remain as moisture
continues to advect from Lake Ontario amidst southwesterly flow.
Active weather continues for the remainder of the long-term, though
none appear to produce blockbuster events. Chances for snow will
continue with temperatures trending towards normal. It does look
like an upper ridge will briefly build in for the middle of next
week, but the pattern looks to quickly return to a strong upper
trough positioned near the Great Lakes.
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Through 06Z Thursday...Challenging aviation forecast for the
next 12 to 24 hours with multiple hazardous, including ptype,
vis/cigs, winds and associated shear/turbulence. All sites
crntly vfr with increasing clouds and winds. Expect light snow
to develop at mss by 09z with ifr conditions, which will spread
toward slk by sunrise. In addition, developing low level jet of
40 to 50 knots will produce areas of shear, especially across
northern NY sites this morning. These winds will help to keep
conditions mainly vfr at pbg/rut/btv thru 18z, before a wintry
mix arrives with vis/cigs trending toward mvfr btwn 18z-00z.
Similar conditions are expected at MPV, while occasional light
snow mixed with sleet occurs at mss/slk with ifr prevailing. As
warmer air develops mixed precip will change to a cold rain by
00z with areas of freezing rain likely with runaway icing
possible, given very cold ground temps. These conditions prevail
overnight into Thursday, with strong low level wind shear and
areas of turbulence, especially near trrn. Expect MVFR
conditionsto trend toward ifr by 06z at many sites.
Thursday: Mainly IFR, with areas MVFR possible. Definite RA,
Thursday Night: Mainly VFR, with local MVFR possible. Slight
Friday: Mainly VFR, with local MVFR possible. Chance SHSN.
Friday Night: VFR. Slight chance SHSN.
Saturday: Mainly VFR, with local IFR possible. Slight chance
Saturday Night: Mainly VFR, with local MVFR possible. Slight
Sunday: Mainly VFR, with areas MVFR possible. Chance SHSN.
VT...Winter Weather Advisory from 5 AM early this morning to 1 AM
EST Thursday for VTZ001>012-016>019.
NY...Winter Weather Advisory from 5 AM early this morning to 1 AM
EST Thursday for NYZ026>031-034-035-087.
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