We're getting close to
that time of year, where many start to wonder about the upcoming winter. I
do want to remind Y'all that this is only September, so there could be
changes in the final outlook that will be posted mid October to early November.
I don't anticipate many changes, but I do want to leave myself some wiggle
room.
Over the few years
I've been doing seasonal outlooks; I've learned what works for Y'all, and have
adapted how these read. This year, I'm staying away from the science and math,
and just using plan speak. I hope this is better understood and appreciated.
Remember, a outlook is
about the general outcome...it is not going to tell you when, who, or how much
any storms will impact.
Fall 2016:
September 2016: Above
average temperatures are expected with below average rainfall. The current
drought will negatively impact fall foliage.
October 2016: above
average temperatures with close to average precipitation. The pattern of above average temperatures will continue into
October. Precipitation will be in the
form of storm systems along with cold fronts. Tropical moisture could bring
need moisture...but that can't be forecasted this far in advance. A few high elevation snow showers in northern
New York State and northern New England.
November 2016:
Slightly above average temperatures along with average precipitation. Precipitation
will be near-normal. We will likely see lake effect snow beginning in Late
November.
December 2016: Average
temperatures and average precipitation. Winter will not really get going until
January. But there could be an event or two somewhere in the Northeast. Lake effect snow will likely be slightly above
normal.
Winter 2017:
The outlook is based
on analog winters that had a similar setup and pattern. It is also based on days of research in other
metrological areas.
Analog years:
1958-1959, 1959-1960, 1977-1978, 1981-1982,1993-1994, 1995-1996, 2000-2001, 2013-2014,
2014-2015.
I came down to four
analogs that matched the closest to what I'm seeing, 1958-1959,1959-1960,
2013-2014, and the top analog was 1993-1994.
Teleconnections:
Let me address the big
elephant in the room. The ENSO .. La Nina is going to be very weak to neutral.
A weak La Nina
increases the odds for a colder winter in the Mid Atlantic and into the
Northeast. The odds across the region are. 60%-70% chance for a cold winter. Snowfall
amounts for the entire region are less clear...about 50%-50% for above average
snowfall. But when you place New England,
New York State, and Pennsylvania in on group and Maryland Delaware, into New
Jersey in another the odds of above average snowfalls increase for New York,
New England and western and northern Pennsylvania.
The warm Pacific Decadal
Oscillation (PDO) is going to make it difficult to allow any kind of La Nina to
make inroads into the pattern. Once we
get into January 2017 the PDO will be the main driver for the Northeast winter
in 2017.
The Warm Atlantic
Mutidecadal Oscillation (AMO). The temperatures in the Atlantic are
ridiculously warm. It will take a while for these to knock back, So they will
be a major influence for November and December, and should negate much of the
cold that tries to come into the region.
Solar Cycle 24
This solar cycle has been
very inactive. Looking back at over 60
years shows years that have low sunspot activity, tend to be weak or neutral La
Nina's, during the winter season.
Here is a look at the
solar cycle and how the 2007 into 2011 ended up quite cold during that time.
2007 into 2011 saw a
very weak solar cycle. This was the quietest the sun had been in over 100
years......During that time we saw cold winters. In 2010 we also had a persistent negative
North Atlantic Oscillation(NAO) and the winter was dominated by a strong
negative Arctic Oscillation (AO).
When the NAO and AO
are in the negative phases, the Northeast tends to see cold outbreaks and we
have an increase in storminess.
My discussion :
September is looking
to see a few colder shots into the Plains mid to end of the Month. But these
troughs of low pressure will lift north and east mostly over the Great Lakes,
and moderating as it heads into the Northeast, So we will see coolness this
weekend into the first of next week...with another shot of cool coming around
the 15th -18th. But the month will end warm.
Seasonal patterns are
strange creatures, most of the same things that caused the hot dry summer and
fall will cause Jan-March to be cold and
snowy. The Jet Stream is strongest in
the winter, due to the temperature difference between the warm and cold air
masses. The Polar Jet normally moves out of Canada and setup up to the south of
the Northeast and Ohio Valley during the winter. As I already said the longwave
(Rossby Wave) length increases in the winter and shortens in the summer,
staying away from the physics and math equations.....it is mainly because of
speed and frequency.
Here is a look at the
summertime and wintertime positions on average.
Here is the Palmer
Drought Index graphic.
This shows how
the jet stream pattern has caused the constant heat dome over the East Coast
this Summer. During the Summer the atmospheric wave lengths shorten up.....but
during the winter the wave lengths get longer.
Another factor for this hot summer, has been the warm Atlantic Sea
Surface Temperatures.
The PDO. A major player is the persistent ridge over the
Rockies this Summer, because of the shorter wave lengths, this lead to a
Midwest trough, with a ridge on the East Coast.
The placement of the warmth in the Gulf of Alaska has been just far
enough west, for the Summer, that the East Coast just couldn't shake the
ridge. So we fried this summer.
Back in the 1950's we
had the same PDO setup, those were cold winters in the Northern CONUS.
The warm PDO will
setup a ridge in the West and a trough over the Great Lakes and East. So cold
air in Alaska, Siberia, and Canada, will be able to slide down that trough into
the Northeast.
We look to see a lot
of cold pooling up in Central and Eastern Canada. With warmer temperatures over
the Gulf states. This would greatly increase the odd of several cold shots out
of Canada, with a active storm track between the two air masses, leaving the Lower
Great Lakes, Northeast, and Mid Atlantic in the battleground for possibility
some sufficient winter storms .
Like 2014-2015 this is
going to be a tale of two winter...the first half will be mild due to the
Atlantic warmth. The second half will be
quite wintery and cold. The Atlantic is
going to be a wildcard this season. All that warmth makes it difficult to
ascertain its impact. So I'm guessing a little more than I normally would.
The Current Sea
Surface Temperature (SST) setup.
Here is a look at the
four top analog years
Here is a blend of all
those winters
You can see the impact
of the setup on 500mb level
temperatures.
I think the analogs
are a little too cold......So I've raised temperature outlooks a little....but
even so, this winter is going to be below average when it comes to temperatures
overall on average.
The bottom line:
The Northeast and Mid
Atlantic is going to see lots of snow this winter. The entire region will see above
average snowfall. Lake Effect Snows, will be well above average.
Here are my charts
showing my thoughts on temperature and snowfall.
I will be posting a
updated outlook for Winter 2016 - 2017 Mid October into the first of November.
Rebecca
