Fear not: White Christmas lookin' good
Snow finally returned to the Inland Northwest last week. However, totals to date are a little below average despite the fast start in September and October. Since the season began, Cliff has measured approximately 10.5 inches of snow, compared to the normal to date of over 17 inches.
From Oct. 28 until the evening of Dec. 10, only 0.1 inches of snow was measured at Cliff’s station in Northwest Coeur d’Alene, while the downtown area did not receive any measurable amount. As I’ve mentioned in previous articles, weather cycles often take six weeks from start to finish. After Oct. 28, we went 44 days without snow, approximately six weeks.
The new pattern with snow arrived during the “full moon” cycle in early December. Cliff and I believe that we should see more snow through the middle to the end of January during this new six-week lunar cycle. After late January, it’s difficult to say how much will fall across the Inland Northwest. A lot depends on the sea-surface temperature pattern in the waters of the south-central Pacific Ocean.
Last week, I compared the solar activity from late 2007 when we started the big snowy year versus late 2019. In terms of the lack of sunspot activity, conditions were very similar to the 2007-08 season when a whopping, record-breaking 172.9 inches of snow fell in Coeur d’Alene.
However, sea-surface temperature patterns are different when comparing December 2007 to December 2019. About 12 years ago, ocean waters were much cooler along the equator and the Pacific Ocean. From late 2007 into 2008, scientists stated that we experienced a strong, cooler La Nina event.
Today, sea-surface temperature data now shows an expansion of a large area of warmer than normal ocean waters in the eastern Pacific Ocean and northward into the Arctic regions. Sea-surface temperatures have been consistently warmer in the Arctic regions since 1990, as much as 5-10 degrees Fahrenheit above normal levels in recent years.
Over the last several weeks, it appeared that sea-surface temperatures were warming up quickly, which had scientists wondering if we were going to see the development of a warmer “El Nino” pattern by early next year. However, there has been some cooling along the equator over the last week, which could open the door to more snow here in the Inland Empire.
During El Nino years, when ocean temperatures are much warmer than normal, most of our precipitation in the Northwest will fall as rain rather than snow. Many of our “open” winter seasons with below-normal snowfall did occur during El Nino years. For example, during the 2015-16 season, only 56.2 inches of snow was measured, with most of it falling in December 2015. And, in 2014-15, another El Nino year, only 36.5 inches of snow was measured, compared to a normal of nearly 70 inches in Coeur d’Alene.
Based on the current data, we are in the in-between cooler La Nina and warmer El Nino event. Most computer models are forecasting “La Nada” conditions into at least early 2020. Previously, most forecasts were leaning toward the formation of a new La Nina earlier this year. Perhaps the recent cooling of ocean waters may point to a new La Nina next year, but most of the forecast computer models are indicating that we are more likely to be heading toward a new El Nino later in 2020. We’ll just have to wait and see.
Our near-term weather has a chance for snow later this week, but there may be some rain mixing in as well. Therefore, there is still the possibility of a chance of a white Christmas across North Idaho. Assuming we do see a white Christmas, it would be the fifth year in a row, a new record since 1895, when at least 1 inch of snow was measured on Dec. 25.
For the rest of the snow season, ocean waters may be too warm for us to get the big snows, but it’s still too early to tell. However, forecasts of continued very low solar activity for at least another year could give us a chance for heavier amounts of snow for the 2020-21 season. Remember, after the big year in 2007-08 with 172.90 inches, the following season with low solar activity had 145.6 inches in Coeur d’Alene.
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Contact Randy Mann at randy@longrangeweather.com