Area Forecast Discussion
Issued by NWS Burlington, VT-- Highlight Changed Discussion --
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FXUS61 KBTV 191138
Area Forecast Discussion
National Weather Service Burlington VT
638 AM EST Sun Feb 19 2017
A weak mid level trough passing to our north across Quebec
today into tonight will bring the possibility of light rain or
snow showers with the best prospect for light precipitation in
the form of snow showers across the Northern Green Mountains and
northern Adirondacks. We`ll see increased clouds for Sunday,
but temperatures will remain in the upper 30s to lower 40s for
valley highs. Dry and seasonably mild weather is expected Monday
and Tuesday with high pressure in place. Another weak mid-
level disturbance approaching from the west will bring chances
for light mixed wintry precipitation Tuesday evening through
Tuesday night. A more significant precipitation system is
possible Friday into Saturday. At this time, it appears the
system at the end of the week will bring windy, mild, and rainy
conditions. Temperatures are generally expected to be above
average this week.
.NEAR TERM /THROUGH MONDAY/...
-- Changed Discussion --As of 638 AM EST Sunday...Some clouds have developed over
portions of the North Country. Temperatures this morning highly
dependent on cloud cover, but generally ranging from mid 30s to
mid 40s. Mid-level shortwave will near the international border
this morning, continuing to increase clouds over northern
portions of the forecast area. This shortwave will sink south
this afternoon, spreading clouds and possibly producing some
light scattered showery activity. Areas that have the best
chance to see precipitation will be western slopes and higher
terrain of the Adirondacks and Northern Greens as W to NW flow
develops over the region. Limited deep layer moisture continues
to reflected in model guidance. Best chance for showers will be
late today into tonight. Combined of limited moisture and warm
temperatures - todays highs in the 40s, lows in the upper teens
to mid 20s by early Monday morning - expect generally 1 inch or
less of snowfall for all areas below 2000 ft. In Northern
Vermont, above 2000 ft, could see 1-2 inches.
On Monday, high pressure moves in at the surface shortly
followed by ridging aloft. This will result in clearing skies
and dry conditions with cooler temperatures in northerly flow.
Max temps expected to range from mid 20s to mid 30s.
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.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 340 AM EST Sunday...Very changeable weather anticipated
during this time frame from ridge of high pres Monday night to
weak system and associated precip Tues afternoon into Weds.
Still looking at a seasonably cool night on Monday with 1030mb
high pres and building ridge aloft...supporting clear skies and
light winds through 06z Tuesday. Have noted thermal profiles
warm aloft with progged 850mb temps approaching 0c by 12z
Tuesday...associated with developing waa on southerly winds on
backside of high pres. Thinking a wide range in temps with lows
ranging from near 0F NEK to near 20F in the SlV...with coolest
values occurring around midnight...then warming as wind shift to
the south by sunset.
Fast moving short wave energy in the westerly flow aloft along
with weakening ribbon of mid level moisture will produce a
narrow axis of rain/snow showers on Tues Afternoon/Night. QFP
will be one and two tenths at best with some downslope shadowing
likely here in the CPV associated with progged 850mb winds of 30
to 40 knots. Best chance of a couple inches of wet snow would be
northern Greens above 2000 feet on Tuesday Night. Progged 850mb
temps warm between 2-4c by Weds...supporting highs well into the
40s with a few 50s likely in the warmer valleys. Additional snow
melt looks likely based on winds and temps Weds...supporting
some rises on local streams and rivers.
.LONG TERM /THURSDAY THROUGH SATURDAY/...
As of 340 AM EST Sunday...The much above normal temp trends
continues into the weekend with developing se conus mid/upper
level ridge of high pres. Latest guidance shows weak disturbance
in the northern jet stream winds aloft crosses our northern CWA
on Thursday...which may suppress some of the warmer
temps...because of clouds/precip. Have continued to mention
mainly terrain focused chance pops on Thursday into
Friday...with any qpf being light. Thermal profiles initially
support a mix of rain/snow...eventually changing to mainly snow
above 1500 overnight Thursday into Friday...as modest low level
cold air advection develops. This cold air advection results in
progged 850 and 925mb thermal profiles falling below 0C by 12z
Friday...supporting highs mainly 30s mountains to mid/upper 40s
Still looking at building heights and developing southerly flow
next weekend...while mid/upper level trof is digging across the
northern Plains. Models have trended slightly slower with system
for next weekend...and are in general agreement with main
surface low tracking from the central Plains into the Great
Lakes...placing us well established in the warm sector. Warm
front feature may produce a light mix of precip on Saturday
Morning...before main frontal band arrives Saturday Afternoon
into Sunday. Strong south/southwest 850mb jet of 50 to 60 knots
will result in some downslope shadowing...especially CPV...and
quick movement of system will limit qpf. Still looking at
widespread precip amounts between 0.25 and 0.75...with temps
warming well into the 40s to mid 50s likely. These temps and
associated rainfall will cause some rises on local
waterways...but way too early to determine overall threat and
.AVIATION /12Z Sunday THROUGH Thursday/...
-- Changed Discussion --Through 12Z Monday...VFR conditions expected to persist
throughout the TAF period with some periodic very light shsn or
flurries potentially affecting higher terrain. Have only
mentioned discrete VCSH at KSLK/KMPV this afternoon/evening.
Overall model performance poor with too much low level moisture
this morning. Expect that trend to continue today and tonight as
water vapor and IR satellite imagery indicate lack of deep
layer moisture. Therefore, any precipitation amounts will be
light and showery activity will be widely scattered.
Winds generally south/southwesterly 6 to 12 knots and
occasionally gusty at KSLK. Winds shift to west/northwesterly
after 16Z today.
Outlook 12Z Monday through Thursday...
12Z Monday through 18Z Tuesday...VFR/high pressure.
18Z Tuesday through 00Z Wednesday...MVFR/IFR in showers/light
mixed precipitation with warm frontal passage.
00Z Wednesday onward...mainly VFR/high pressure.
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