Area Forecast Discussion Issued by NWS Burlington, VT
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000
FXUS61 KBTV 030218
AFDBTV
Area Forecast Discussion
National Weather Service Burlington VT
918 PM EST Tue Mar 2 2021
.SYNOPSIS...
A roller coaster ride of temperatures will occur over the upcoming
seven days with a series of frontal passages and shortwave troughs
finally exit to the east early next week. Periods of light to
moderate snowfall will occur tonight through tomorrow over much of
northern New York with lighter amounts in northern Vermont. From
Thursday through Sunday we will see cold and occasionally breezy
conditions with scattered mountain snow showers, followed by a
significant warm up beginning on Monday.
&&
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
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As of 918 PM EST Tuesday...Dynamic support continues to
increase over the area in response to a well defined shortwave
trough over eastern Ontario. This feature is headed right for
our area and atmosphere continues to moisten over northern New
York and Vermont as dew points increase and some snow starting
to be reported over northern New York. Areal coverage will
continue to increase as the night wears on and forecast for
accumulating snow overnight is on track. No big changes needed
at this time.
Previous Discussion...
A quick hitting snowfall for much of northern New York with
lighter amounts into northern portions of Vermont is expected
tonight. High confidence in a pocket of 4 inches of snowfall
given the latest HREF (High Resolution Ensemble Forecast)
probabilities, with mean 12 hour snowfall ending 7 AM tomorrow
exceeding this value over much of Saint Lawrence and Franklin
counties in New York where a winter weather advisory has been
issued. Leaning towards the finer scale model guidance that has
heavier precipitation amounts than coarser models, chances are
with the relatively small spatial footprint of moderate snowfall
we could see some locally greater snowfall upwards of 6 inches
where heavier snowfall rates set up for longest duration.
In terms of the evolution of the snow, it looks like some light snow
will break out from west to east between 9 and 11 PM in northern New
York and may be a bit spotty with very dry low-level air helping
evaporate much of the snow. Then there may be a break followed by
moderate, steadier snowfall after midnight driven by significant
warm air advection evidenced by veering wind profiles within an
increasingly moist, deep layer ahead of a decaying clipper sliding
through southwestern Quebec. Enhanced precipitation amounts upslope
of the Adirondacks seem reasonable with a mean 30 knot 925
millibar westerly wind. Gradual top-down drying and resulting
end of steady snowfall will occur during the morning as forcing
for ascent weakens. However, additional light snow will may
redevelop over this area, and possibly over a broader part of
the North Country, with some upper-level divergence and further
deepening of the cloud layer ahead of a weak cold frontal
boundary. With much of the day featuring warm advection across
the region, temperatures will recover to near or above normal.
Then behind the cold front tomorrow night, we will see a return
of colder and breezier conditions, although not nearly as
intense as our recent arctic blast.-- End Changed Discussion --
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.SHORT TERM /THURSDAY/...
As of 307 PM EST Tuesday...Quiet and seasonably cold weather
continues on Thursday. Partly to mostly sunny skies are expected
with persistent and modestly gusty north flow as we remain
between strong upper Great Lakes high pressure and distant low
pressure across Labrador. Highs to range through the 20s.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
As of 307 PM EST Tuesday...More or less a persistence forecast
will be offered during late week into next weekend. The overall
theme remains the same as pronounced downstream blocking over
the North Atlantic westward into the Greenland/Davis Strait
region fosters a seasonably deep upper trough across
southeastern Canada and the Northeastern US. As such, late
winter cold looks to continue through Sunday under persistent
light to modest northerly flow. I`ve continued to mention some
nominal snow shower chances across the northern mountains
Thursday night into Friday with the passage of a weak surface
trough feature. Thereafter mainly dry weather returns with no
organized or significant precipitation events expected. Highs
through the period to range from the upper teens through the 20s
with lows mainly in the positive single digits and teens.
Looking further out, there remains a building consensus the the
downstream block will give way by Monday onward into next week with
a significant moderation in temperatures as Pacific air streams
eastward across the lower 48.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Through 00Z Thursday...VFR conditions are expected through about
04z with ceilings and visibilities lowering as clouds and snow
move into most of the area. Between 04z and 12z visibilities
will lower into the IFR category at KMSS, KSLK, KPBG, and KBTV
before slowly improving into the MVFR and VFR categories by 18z.
Visibilities at KMPV and KRUT will be VFR through the entire
period as any snow is expected to be light and not have an
impact on visibilities. Ceilings will be lowering into the 1500
to 3000 foot range at all locations between 04z and 12z and will
slowly improve after 18z. Expect low level wind shear over parts
of the area with strong westerly flow at 2000 feet tonight
through 12z before winds aloft weaken during the remainder of
the period.
Outlook...
Wednesday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Thursday: VFR. NO SIG WX.
Thursday Night: VFR. Chance SHSN.
Friday: VFR. Chance SHSN.
Friday Night: VFR. Slight chance SHSN.
Saturday: Mainly VFR, with local MVFR possible. Chance SHSN.
Saturday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Sunday: VFR. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...Winter Weather Advisory until 7 PM EST Wednesday for NYZ029-
030.
&&
$$
SYNOPSIS...Kutikoff
NEAR TERM...Evenson/Kutikoff
SHORT TERM...JMG
LONG TERM...JMG
AVIATION...Evenson