I love it when forecasters let their love of snow show
through…
Area Forecast Discussion
National Weather Service Burlington VT
322 PM EST Fri Mar 11 2022
.SYNOPSIS...
A potent storm system will impact the region tonight through
Saturday night with moderate to heavy snow and blowing snow
expected. Gusty winds are expected Saturday night and Sunday morning
as well which will create areas of blowing snow and possibly some
power outages. Winds will abate Sunday afternoon with a warming
trend expected through next week and temperatures approaching 60
degrees by the end of the week. No significant precipitation events
are expected after the Saturday snowstorm.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
As of 319 PM EST Friday...Bottom line up front...Winter Storm
Warnings remain in effect across the entire region for tonight
through the first half of Saturday night with a widespread moderate
to heavy 6-12" of snow expected. Unless you live under a rock,
you`ve likely read about this storm several times over the past few
days. So with that in mind, I`m going to skip a lot of the synoptic
overview and mesoscale details this afternoon and just get down to
brass tax and talk about what`s changed, the expected amounts, and
impacts.
So what`s changed. Synoptically not much. Trends from yesterdays
guidance for a delayed phasing of a northern stream trough and
southern stream energy continued into the 00Z NWP model suite, and
with the 12Z runs everything is basically locked into the slightly
eastward shift we talked about yesterday. But now that we`re into
the wheelhouse of higher resolutions models, we`re able to put some
more detail into the forecast, specifically the QPF which is good
and bad if you`re a snow lover or not. Since I`m a snow lover, I`m
going to say more snow is good, less is bad.
So where are the goods? Eastern Vermont and the northwest slopes of
the Green Mountains continue to be the bullseye for moderate to
heavy snow as low/mid-level frontogenetical forcing will be maximized
here Saturday afternoon within the northwest quadrant of the surface
low bombing out over Cape Cod. This is shown nicely in the SPC HREF
snowfall rates which highlights several hours of 1-2"/hr from about
noon through 4 PM. Additionally, when the flow shifts to the
northwest Saturday evening and overnight, favorable blocking will
allow upslope snow to persist and decrease in density adding on
additional accumulations into Sunday morning. A widespread 8-14" is
expected across this area, with locally up to 20" across the higher
peaks from Appalachian Gap to the Canadian border.
And what about the bad you ask? Well, based on the latest trends
we`ve had to adjust QPF and subsequent snowfall amounts down the St.
Lawrence and Champlain Valleys. For the St. Lawrence, with the
eastward low track and a tighter precipitation gradient it`s only
looking like about a half inch of QPF there for the event, resulting
in snow totals of around 6" to maybe 8" where the terrain begins to
slope upward to the Adirondacks. In the Champlain Valley, a faster
shift to northwesterly flow results in some downsloping and also
lower QPF of about 1/3 to 2/3 of an inch. The greatest downsloping
will occur on the NY side of the valley and in Grand Isle county
where storm total snow will range from 6-8", while 6-10" is more
likely on the VT side.
Finally, the bad for everywhere will be the winds. As snowfall
begins to taper off from west to east Saturday evening gusty winds
will develop as a strong low-level jet materializes over the region
and the atmosphere becomes deeply mixed. Forecast soundings continue
to indicate mean mixed layer winds of 30-40kts resulting in surface
gusts at a minimum of 30 mph and more likely closer to 40 mph for
many locations. Blowing snow will become a big concern for those
traveling Saturday evening through Sunday morning given these
conditions and for a short period late Saturday afternoon into the
evening dare I say near blizzard conditions may be seen with
visibility less than a half mile. Power outages also remain a
concern, especially across the lower Connecticut River Valley where
heavy wet snow will be seen but based on the latest trends of
lighter snow for the latter half of the event, thinking only
isolated outages look more likely now.
