1. Researcher: Number of blizzards doubled in past 20
years
Doyle Rice, USA TODAY 2:27 p.m. EST January 24, 2016
Snowstorms like the historic blizzard that lashed the East Coast (/story/weather/2016/01/24/east-­coast-­
blizzard-­aftermath/79259922/) this weekend may be more numerous than they used to be.
The number of blizzards each year has doubled in the past two decades, according to preliminary research by
geographer Jill Coleman
(http://cms.bsu.edu/academics/collegesanddepartments/geography/facultyandstaff/colemanjill) at Ball State
University in Muncie, Ind.
From 1960-­94, the United States averaged about nine blizzards per year. But since 1995, the average is 19
blizzards a year, she said. The increase could stem from better reporting and monitoring of the storms, among
other theories, Coleman said.
USA TODAY
Battered East Coast begins digging out from deadly blizzard
(http://www.usatoday.com/story/weather/2016/01/24/east-coast-blizzard-
aftermath/79259922/)
Overall since 1960, more than 700 blizzards have occurred in the U.S., excluding Alaska and Hawaii.
For a snowstorm to be classified as a blizzard, it must meet these criteria: Heavy or blowing snow, sustained winds of 35 mph and visibility of one-­
quarter mile or less — plus all three conditions must persist at least three hours. Washington, D.C., met those three conditions Saturday, according to
data compiled by Capital Weather Gang.
Coleman said there's a chance the increase in blizzards could be tied to sunspot cycles. Her research found blizzards tend to increase during periods of
low sunspot activity.
"Sunspot-­minimum periods tend to coincide with more frequent polar outbreaks in the Northern Hemisphere that could increase the likelihood for blizzard
occurrence," Coleman said. "However, sunspot activity is only a small component in explaining the frequency of blizzard occurrence."
The number of sunspots visible on the sun waxes and wanes with an approximate 11-­year cycle, NASA said. Sunspot activity was low in the mid-­1990s,
the mid-­2000s and is low again now.
Brad Anderson, a meteorologist from Lincoln, Neb., not associated with Coleman's research, agreed that blizzards appear to go in cycles, noting there
were lots of blizzards in the 1970s but fewer in the 1980s. He said blizzard frequency can be linked to changes in large-­scale climate patterns in the
ocean and the atmosphere.
Coleman agreed with Anderson that these large-­scale climate patterns could be the bigger driver of blizzard cycles.
Coleman's research, of which she is the lead author, is preliminary and undergoing review in a peer-­reviewed journal. More investigation is needed to
determine other reasons for an increase in the number of blizzards, she said.
More blizzards are also occurring outside the traditional season of October to March, Coleman's research found. There were three more blizzards per
year from April to September in the past two decades, as compared to 1960-­94. Most "out-­of-­season" blizzards occurred in the northern Plains.
Blizzards have been reported in all months except September and August, but most occur in December, January, February and March.
While big blizzards that hit the East Coast make the news, most occur in the sparsely populated northern Plains and upper Midwest, especially in the
Dakotas and Minnesota.
Winter storm wallops eastern USA
Fullscreen
(Photo: Seth Harrison, The Journal
News)

2. Only six states have never recorded a blizzard — Alabama, Florida, Louisiana, Mississippi, South Carolina and Tennessee, Coleman said.
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