Winter Storm Trends for the United States

Heavy snowstorms have the ability to paralyze cities, cause power outages and result in billions of dollars in economic losses. For example, the Groundhog Day Blizzard of 2011 that impacted several central, eastern and northeastern states resulted in an estimated cost of two billion dollars and 36 human casualties.

As we head into the fall and winter seasons, you may be wondering if the United States is experiencing fewer of these major winter storms today than we did in the past. The answer? It’s complicated. Even in a warming world, extreme snowfall events will continue to occur. Our planet’s rising thermostat has altered the overall rate of precipitation and increased the amount of winter precipitation falling in the form of rain instead of snow. But while total snowfall may be on the decline, scientists have also discovered that there were twice as many extreme snowstorms in the past half century as there were in the preceding one.

The National Climate Assessment outlines several trends in winter storms and snowfall in the United States:

  • Winter storms have increased in frequency and intensity in the Northern Hemisphere since the 1950s, and storm tracks have slightly shifted towards the poles.
  • Over the last century, extremely heavy snowstorms have increased in number in the eastern and northern portions of the United States; however, over a smaller time scale (the last 15 years), extremely heavy snowstorms have decreased in frequency for the same area.
  • Total snowfall has decreased for the southern and western regions of the United States, increased for the northern Great Plains and Great Lakes, and not changed in areas such as the Sierra Nevada.
  • Very snowy winters have decreased in frequency for most regions over the last 10-20 years, with the exception of the Northeast, which has seen normal numbers of such events.
  • Snow cover has decreased in the Northern Hemisphere, in part due to higher temperatures.

Variation of Storm Frequency and Intensity during the Cold Season

Variation of winter storm frequency and intensity during the cold season (November-March) for high latitudes (60-90°N) and mid-latitudes (30-60°N) of the Northern Hemisphere over the period 1949-2010. The bar for each decade represents the difference from the long-term average. Storm frequencies have increased in middle and high latitudes, and storm intensities have increased in middle latitudes.

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Learn how to protect your family and property before, during and after a winter storm.

Sources:

  • Melillo, Jerry M., Terese (T.C.) Richmond, and Gary W. Yohe, Eds. 2014. Climate Change Impacts in the United States: The Third National Climate Assessment. Washington: U.S. Global Change Research Program. http://nca2014.globalchange.gov/.
  • NOAA. 2008. Winter Storms: The Deceptive Killers. Washington: US Department of Commerce. http://www.nws.noaa.gov/om/winter/resources/Winter_Storms2008.pdf,
  • NOAA. 2015. "Billion-Dollar Weather/Climate Disasters." Accessed September 15 http://www.ncdc.noaa.gov/billions/.
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