FXUS61 KBTV 170559
AREA FORECAST DISCUSSION
National Weather Service Burlington VT
159 AM EDT Sun Mar 17 2019
A weak front will cross the area this evening with a period of
numerous, mainly mountain snow showers. Thereafter, high
pressure generally dominates sensible weather conditions into
the middle of next week with mainly dry weather and seasonably
.NEAR TERM /THROUGH TONIGHT/...
As of 1017 PM EDT Saturday...The weak secondary front is
crossing the region at this hour, producing an area of snow
concentrated across southern Clinton County NY eastward into
Chittenden, Lamoille, and Washington Counties in VT. Latest
observation indicates snowfall already up to 0.3 inch at BTV,
and while the band is moving very slowly southward, it should
still produce another half inch to inch as it progresses. Have
increased PoPs and snow totals in the aforementioned areas to
match the latest radar trends, though this still gives most
spots 2 inches or less overnight. Upstream obs indicate
temperatures in the teens to around 20, so forecasted overnight
lows still look good. No other changes were needed with this
Previous discussion...Scattered light snow showers and flurries
continue across the area this afternoon under broad cyclonic
flow aloft and westerly flow at the surface. Variably cloudy
skies persist as temperatures have trended steady or slowly
fallen over the past 6 hours under steady cold thermal
advection. The forecast headed into tonight remains largely on
track. Both global and CAM output maintain consistency in
showing a secondary surface trough passage later this evening
along with a general reblossoming of light snows/snow showers,
mainly across the Adirondacks and to a lesser extent the
northern Greens. Here, overnight minor accumulations should
range in the dusting to 2 inch range with localized totals to 3
inches or so in most persistent activity. Given the low level
flow will lie within 30 deg. of westerly the broad valleys and
southern VT counties should largely stay clear of the steadier
pcpn with just a passing light snow shower or a few flurries
expected. Low temperatures to range from 10 to 20 above with
local variability as winds abate and veer slightly northwesterly
Mainly quiet and seasonably cold weather is then expected for Sunday
into Sunday night. We remain under large-scale upper troughing aloft
though broad surface ridging building east from the Great Lakes and
Ohio Valley will keep the boundary layer on the dry side. A weak and
final trough passage will occur Sunday night with little fanfare
other than a brief window of mountain flurries/light snow showers.
Coverage should be considerably less than this evening`s feature
with limited available moisture. As mentioned we`ll be on the chilly
side by mid-March standards as daily highs range from the mid 20s to
lower 30s and overnight lows bottom out in the 8 to 18 above range
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 254 PM EDT Saturday...Broad cyclonic flow will continue across
the North Country Monday and Tuesday with an upper level trough
anchored across the region. Several weak shortwaves are
expected to rotate through the trough but given the lack of
available moisture, any shower activity looks marginal at best.
With the trough anchored overhead, a modified arctic air mass
will remain in place which will bring the return of below normal
temperatures to the region. Temperatures on Monday and Tuesday
will warm into the mid 20s to lower 30s with overnight lows
Monday night in the single digits to mid teens. This pocket of
colder air will continue to modify through Tuesday before a
shortwave ridge begins to displace the trough Tuesday night.
This will yield some warmer overnight temperatures Tuesday night
as temperatures will only drop into the upper single digits to
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 254 PM EDT Saturday...Another short-lived pattern change will
take place on Wednesday as a low-amplitude ridge works it`s way
into the region. There will be pretty significant warm air
advection in the 925 mb to 850 mb layer as flow aloft switches
to the west/southwest. This will allow temperatures to warm back
into the 40s across the North Country Wednesday and again on
Thursday but cloud cover will accompany the warm up as the
southwesterly flow ushers in an increase in moisture. On
Thursday, models have been in good agreement with bringing a
potent cold front attached to a surface low over Newfoundland
through the North Country. As this happens, an upper level
trough over Canada will sharpen and quickly drop southward to
boost some dynamics associated with the approaching cold front.
Nevertheless, PWAT values less than 0.4 inches will really limit
much of the rainfall/snowfall accumulation.
The main impacts from this new trough will be felt Friday and
Saturday as another arctic air mass descends across the region.
Looking at 850 mb temperatures (better proxy than 500 mb thickness
this time of the year), temperatures on Friday and Saturday will
likely struggle to warm into the mid 20 to mid 30s. Overnight lows
on Friday night will be unseasonably cold with temperatures dropping
into the mid single digits to mid teens under partly to mostly clear
skies. However, there is some good news for those ready to
experience more spring-like weather. High amplitude ridging will move
over the North Country Saturday night into Sunday with temperatures
expected to warm 10 degrees or so from those seen Friday night.
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Through 06Z Monday...Snow showers are diminishing over the area
early this morning after a band of heavier snow pushed through
over the last couple of hours. Expecting KMSS/KPBG/KRUT to be
mainly VFR through the remainder of the TAF period. KSLK, KBTV,
and KMPV will see snow showers lingering a littler longer
through the overnight hours, but expecting all of these sites to
trend VFR between 08Z and 12Z as snow showers end. After a
mainly dry end to the morning, HiRes models are indicating some
scattered snow showers redeveloping during the afternoon hours.
While conditions are expected to be primarily VFR through the
afternoon, any terminals that do see some passing snow showers
will see a temporary reduction to MVFR/IFR visibilities and
ceilings. Between 00Z and 06Z tonight, expecting a slight
increase in snow shower activity over northern New York
terminals as a weak upper wave moves through.
Light westerly winds will continue through the morning, then
increase into the afternoon with some gusts 10-20 mph possible
between 15Z and 21Z. Winds will diminish after 00Z as high
pressure builds in.
Monday: VFR. NO SIG WX.
Monday Night: VFR. NO SIG WX.
Tuesday: VFR. NO SIG WX.
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.
Wednesday Night: VFR. Chance SHSN.
Thursday: Mainly VFR, with local MVFR possible. Chance SHRA,
As of 250 PM EDT Saturday...The Flood Watch for ice jams has
been cancelled as of mid-afternoon. Most rivers have crested and
are steadily falling as of this typing. While we can`t rule out
some isolated additional ice movement, cooling temperatures and
limited additional snowmelt have largely ended the threat