Past helps us predict snow on holidays

Early this week, our first major snow was seen across the Inland Northwest. After today, we’ll pass the Thanksgiving holiday and be heading toward Christmas. The big question I’m starting to hear is, “Are we going to have a white Christmas?”

As mentioned in previous articles, the La Niña cooler than normal sea-surface temperature event in the south-central Pacific Ocean continues to maintain its strength. During the last La Niña event, our region saw record snowfalls. By contrast, during El Niño years, we typically see milder winter seasons with more rain than snow falling in the lower elevations, as was the case last winter.

Based on current weather patterns, with a moderate La Niña and low solar activity, I believe the chances for that white Christmas are better than 50-50 in the Spokane area and about 70 percent in Coeur d’Alene.

December 2008 was incredible in terms of snow and cold. At the airport, 61.5 inches fell, nearly 20 inches above normal for the entire season. On Dec. 25, 20 inches of snow was on the ground. December 2008 was very chilly as the average temperature was 5.3 degrees below normal. Although December 2009 was colder than normal, only 6.7 inches of snow fell.

The most snow ever measured on Dec. 25 at Spokane International Airport was 23 inches in 1951. Nearly three feet of snow was gauged in parts of North Idaho on that date. In 1996, 19 inches was measured at the airport with 10 inches on the ground in 1992, 1987 and 1916.

Speaking of a white Christmas, since records were kept at Spokane International Airport, we had 61 days with over a trace of snow on the ground on Dec. 25 since 1881. In Coeur d’Alene, there have been 82 days since 1895 with over a trace of snow on the ground.

The chances for snow in our region are good during the full moon phase of Dec. 21-29. This time frame may also bring us another round of much colder temperatures across the Inland Northwest. As I mentioned last week, I still see at least 20 percent above normal snowfall between now and late January.

Happy Thanksgiving!