By Nic Loyd, WSU meteorologist, and Linda Weiford, WSU News
Temperatures have been running warmer than usual in December, driven mostly by a strong El Nino brewing in the tropical Pacific. The result is a west-to-east jet stream delivering mild Pacific air across parts of the country, including here in the Evergreen state.
Deep breath, snow lovers. There’s a good chance El Nino won’t steal our white Christmas. A temporary shift in weather from warmer-than-usual to cool suggests the odds are improving that snow will be on the ground in eastern Washington on Christmas day.
Let’s start by looking at what constitutes a white Christmas, as defined by meteorologists. Unlike in the United Kingdom where the minimum requirement is a few falling snowflakes any time during the day, here in the United States at least one inch of snow must be on the ground that morning.
That said, the last time Spokane, Pullman and surrounding communities awoke to a white Christmas was in 2012, courtesy of a winter storm that dumped five inches of snow a few days earlier.
In 2011, a trace of snow covered the ground, and in 2010, we had three inches. In 1998 and again in 2008, it snowed more than half a foot in the Spokane area beginning on Christmas Eve.
Last Christmas, we experienced more of a greenish-brown wonderland, due to a 21 consecutive day warm spell in December. Temperatures in the region ran four degrees above normal for that date and we saw no snowpack or precipitation.
Communities that typically enjoy the whitest Christmas on any given year include Mazama, located near the north central part of the state, and Winton, six miles south of Lake Wenatchee State Park. Located on the eastern slopes of the Cascade Mountains, where snow falls at a robust pace during winter, the two places average 3-4 feet of snowfall each December.
Here in the Spokane area, we should get a blast of cooler weather and some accompanying snow. What we don’t know is if a rise in temperatures will melt the snow that so gracefully collects on fence posts, holiday wreathes and ponderosa branches.
Then again, when it comes to Christmas, it might be good to remind ourselves that it’s the spirit that counts, not the depth of snow in our front yards.
Weathercatch is a bimonthly column published in the Spokesman Review