Just a quick update on the coming winter of 2016-2017.
Snow cover:
I've been talking a lot about snow cover, and how the greater the Eurasian snow cover grows from the 60 degree
line south, during the month of October, the greater the likelihood for a cold
winter in the East Coast CONUS.
Siberian Snow Cover extent. is very impressive. You can see this year snow
cover is 2nd only to 2014-2015, which was a very cold and snowy winter. You
will notice that the snow growth in 2015 was close to this year. But if you
remember, winter 2015-2016 was dominated by the Super El Nino, which was so strong
it overrode all the other teleconnections. This year the other teleconnections will be in play.
While I can find no real correlation between Canadian snow cover
and East Coast winters. You can see the
extent of snow cover in Canada is notable. There is a lot of snow on the ground
in Southeast Canada. This can only help, to keep the winter air mass over the
northeast colder.
Blocking:
The North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) are both in a negative
phase right now. So this is leading to
blocking over eastern Canada and Greenland. Because of this these Canadian
weather systems moving into the Northeast are much slower to depart. Therefore
we tend to hang onto the cold longer. We will see this happen this coming weekend, as the Midwest and Mid Atlantic States heat up, while the Northeast stays a little cool.
The Southern Oscillation Index (SOI) is isolating back and
forth. But it did jump start this pattern to a wintertime one.
Years that have weak La Nina's or have neutral conditions
tend to be more prone to Greenland blocking.
So the Northeast sees more cold outbreaks, as well as a slowing down of
the Clippers and Coastal storms, which helps the odds of seeing greater snow
amounts.
I talk a lot about atmospheric patterns, and how they are
cyclical in nature. When a pattern looks
similar to ones in the past, it is logical to expect a similar outcome. The
pattern we're now in is similar to the
1950's into the 1960's.. I made my 2016 hurricane outlook based on analogs from
the 50's and 60's. So far I've nailed
the hurricane season this year... only missing out of a major hurricane
CONUS landfall ( but to be fair, I only missed that one by a mere 12 miles).
If you look at my winter outlooks for 2016-2017 you will see
that there are a lot of analog years from the 1950's and 1960's. In fact if you
do a reanalysis of those years, you will see there is a striking similarity
between this year's setup and those years. you will also see how my thoughts have evolved and clarified. But overall, there hasn't been a lot of change from what I posted in September, or even before that on my Facebook Weather Page.
The northern hemisphere arctic is warm this year (as
compared to average). But years that had
a lot of warmth in the arctic, tended to be cold, with lots of blocking.
I showed the other day, on my Facebook Weather Page, how the
pattern is shaping up, with the trough in the Atlantic pulling west, the ridge
over the East Coast and the trough off
the West Coast are also pulling west. I
said watch the trough in the Pacific Northwest, when it pulled west and
deepened that was the sign that winter would begin. All of that is currently in play.
The extent of cold in Eurasia is almost unprecedented. While
the CONUS has been quite warm. But that
is about to change. The pattern change that has been occurring now for about a
week, will continue. The cold in Siberia
will make its way into the Lower 48 by way of the northern jet. I've
been saying that I expect the current pattern change to be in place by the Middle
of November; I see nothing that is changing my mind. In fact December could end
up being very cold, very cold indeed. With the high likelihood of blocking in
the North Atlantic, we have a shot at a few decent snow events between
Thanksgiving and Christmas. I've been showing charts that show the Euro's long
range ideas. The other day I made a chart that showed the typical La Nina storm
tracks.
The Euro long range control and mean are showing a lot of
snow through Mid December.
I have very little doubt about how winter 2016-2017 is going to turn out. It's going to be a colder and snowier winter here in the Northeast and Mid Atlantic States. December looks to be very cold. All and all, Northeast Maine and far eastern New England look to average out around normal.
The Great Lakes are very warm, for this time of year. So
once we see more frequent cold outbreaks over the next few weeks, I expect to
see lake effect snow falling across western, Upstate New York and western
Pennsylvania.
Here are my updated temperature and snowfall ideas. For the snowfall outlook, I've added percentages to make it a true forecast. The snowfall is from first flake to last flake (including what we've already seen this month).
