Weathercatch: Rare pre-Thanksgiving blizzard struck Inland Northwest in 2010

<p><p>A blizzard warning issued in November is unusual in itself. Add the early timing to the Spokane region, and it’s plain rare. Yet that’s just what happened 11 years ago this week as a poorly timed storm system approached the Pacific Northwest just a few days before Thanksgiving and the busiest travel time of the year.</p></p><p><p>In 2010, the National Weather Service told people to prepare for a blizzard on Monday, Nov. 22, through the next day. It was the first blizzard warning the Spokane office had issued since opening in the mid-90s, meteorologist Mike Fries told the Associated Press.</p></p><p><p>A storm system packing strong winds, snow and cold temperatures was expected to hit parts of Eastern Washington and the Idaho Panhandle, Fries explained, and it was the intensity and duration of winds that would elevate the storm to a blizzard.</p></p><p><p>In fact, although many people associate blizzards with the accumulation of heavy snowfall, it’s more about high winds and low visibility due to blowing snow. The weather service defines a blizzard as a combination of high winds with snow or blowing snow that reduces visibility to less than ¼ mile for at least three hours.</p></p><p><p>Which is just what happened Nov. 22-23, 2010. Wind-whipped snow created dicey road conditions, delayed flights and caused many schools to close.</p></p><p><p>Snowfall amounts ranged from 3 inches near Wenatchee to upward of 7.5 inches in Spokane. Even Yakima – nicknamed the Palm Springs of Washington – got a 5-inch heaping.</p></p><p><p>All the while, winds howled with gusts higher than 40 mph in some locations. The resulting snow drifts, low visibility and car wrecks caused temporary road closures, including a 26-mile stretch of Highway 27 from Spokane to Whitman county. In Waterville, located 135 miles west of Spokane, winds reportedly blew snow sideways, burying parked and stranded cars in blankets of white.</p></p><p><p>By the time snowfall stopped on Nov. 23, temperatures ran 34 degrees below normal for that date. Two days before Thanksgiving, the high temperature in Spokane made it to only 11 degrees, and the low dipped to a frigid minus-10 degrees.</p></p><p><p>Snow, high winds and extreme cold don’t typically occur at the same time in our region – especially when it’s autumn, not winter. And while the Inland Northwest is no stranger to snowstorms, blizzards are another story.</p></p><p><p>The Great Plains and Upper Midwest are the most common locations for blizzards to occur in the United States, according to the National Weather Service. So what happened here?</p></p><p><p>The stage was set for a blizzard when a mass of Arctic air plunged southward into Washington and clashed with a surface low pressure system packed with warm, moist air off the coast. The winds were due in large part to the stark difference between the low pressure of warmer air and the high pressure of bitter-cold air. Also, as moisture from the coast collided with cold air from the north, precipitation fell as snow instead of rain when the storm system moved inland. (A record-setting 2.5 inches of snow fell in Seattle, bringing the city to a near standstill with people stuck in traffic for five hours.)</p></p><p><p>Fortunately, weather conditions leading to this Thanksgiving are more tranquil. No extremes are forecast for our region so far this week. We’ll see some clouds and a light mix of rain and snow, but no snowstorms, blustery winds or black ice on roadways.</p></p><p><p>Considering that Thanksgiving travel is up 13% over last year, according to AAA, Mother Nature has dished out a kind deed.</p></p><p><p>———</p></p><p><p><em>Nic Loyd is a meteorologist in Washington state. Linda Weiford is a writer in Moscow, Idaho, who’s also a weather geek. Contact: ldweiford@gmail.com.</em></p></p>