Snow With El Niño This Winter? Here's What Forecasters Think

SEATTLE, WA - Spend a few winters in Puget Sound and you'll to notice a pattern in lowland snow events: One year, nothing. The next two years, one big snowstorm in November, and then just lots of rain.

In other words, you can't count on snow, an already rare weather phenomenon near sea level in the Pacific Northwest.

This winter, we're in for a slight change. The National Weather Service (NWS) is predicting a 70 percent chance we'll have an El Niño winter, which is the opposite La Niña we've had since May 2016.

This week, the Seattle Weather Blog and chief Seattle NWS meteorologist Jay Albrecht both predicted strong starts to winter, and that might include snow.

"Our prediction? The first half of winter will be wet, with a noteworthy snowstorm by mid-January. Why? Borderline weak El Niño, similar to 2006-07, 2003-04 and 1979-80. All those winters had great snowstorms in first half," Seattle Weather Blog's Justin Shaw posted on Twitter this week.

You'll notice that Shaw called the coming El Niño "weak." That means temperatures in the middle of the Pacific Ocean will be warmer than average, but not by much. During a normal El Niño, water temperatures can rise as much as 2 degrees, warm enough to push the jet stream north (and keep it there), bringing warmer air and less rain to the Pacific Northwest over the winter months.

In a weak El Niño, the jet stream has the ability to shift south, allowing colder air and moisture into the region - and thus the chance for snow. Will a weak El Niño mean more snow for Puget Sound this winter? Some weak El Niño years have had big, one-time snow events. The 1979-80 weak El Niño winter clocked 12-1/2 inches of snow. But, for example, the winter Puget Sound saw the most snow (1968-69, 67 inches at Sea-Tac) was a regular El Niño.

Here's a look at NWS data on snowfall totals in either El Niño or La Niña winter years:

• 2017-18: 4 inches, La Niña
• 2016-17: 11.2 inches, La Niña
  
• 2015-16: 0 inches, El Niño
• 2014-15: 0.8 inches, weak El Niño
  
• 2013-14: 4 inches, La Niña
• 2012-13: 0.6 inches, weak La Niña
  
• 2011-12: 10.5 inches, La Niña
• 2010-11: 7.8 inches, La Niña
  
• 2009-10: 0 inches, El Niño
• 2008-09: 23.3 inches, La Niña
  
• 2007-08: 3.5 inches, La Niña
• 2006-07: 3.6 inches, weak El Niño

Caption: Joe Farhat, an employee at a produce stand in Pike Place Market, sleds down a closed snow-covered street Jan. 18, 2012 in Seattle.

Photo by Stephen Brashear/Getty Images