Last year, the Northwest. was enduring another season of moderate to heavy snow. Many of us remember the wet weather pattern that began in November 2010 and continued into late spring. During that time, only February had below average moisture.
November had below-normal precipitation at Spokane International Airport; only 1.73 inches fell, .57 inches below average. Since Nov. 25, many areas in our region turned completely dry with only traces to a few hundredths of an inch of moisture reported.
According to the National Weather Service, the first 14 days of December have been extremely dry with only .01 inches of moisture in Spokane. Normally, the airport receives close to an inch of rain and melted snow Dec. 1-14. There are a number of locations in the Northwest that have not even reached one-tenth of an inch, and that includes Seattle. The Sea-Tac Airport has received only 0.03 inches as of Dec. 13.
Many computer models keep changing the overall weather pattern to the wetter side. But the strong high-pressure ridge off the Pacific Northwest coastline keeps hanging onto life. However, the latest information does bring an increasing chance of snow across the Inland Northwest over the next several weeks. We should finally see snow in the Spokane and Coeur d’Alene area this week.
December has started off cooler than normal in the Western U.S. Many places are in the top 10 in terms of their coldest maximum, minimum and average temperatures for early December. Sea-Tac and Olympia both saw their average low temperatures for the month break into the top 10 coldest for November. In Spokane, the average temperature for early December was near 27 degrees, about 1.5 degrees below normal.
A La Niña event does not guarantee a snowy winter for the Northwest and southwestern Canada. There have been a few La Niña years with below-normal snowfall totals. The difference during those seasons was the increased solar activity, similar to what we have now. It’s still possible that we’ll get cranking with increased snowfall later this month and January. I still believe that snowfall totals for this season should be near or even slightly above normal levels.