Major weather change coming
After approximately 4 1/2 months of very dry conditions across the Inland Northwest, a new wetter weather pattern is already bringing some much-needed moisture to our region.
Some of this recent dryness has been blamed on the strengthening El Niño in the south-central Pacific Ocean. This abnormal warming of sea-surface temperatures near the equatorial regions ultimately alters upper-level jet stream flows across most of the Northern Hemisphere and determines whether we see wetter or drier conditions.
No one is certain as to why ocean waters warm up and cool down. I believe that short and long-term climatological cycles and underwater volcanic activity may play a big part to the formation of an El Niño and La Niña (the abnormal cooling of sea-surface temperatures).
During weak El Niño events, we are typically drier and cooler than normal. But, as this new warm-water phenomenon gains strength and becomes moderate in intensity, we typically turn warmer and wetter than average. Over the past several weeks, sea-surface temperatures in the south-central Pacific Ocean have been warming up at a rapid rate. The latest charts do indicate that El Niño is now or will soon become a moderate event.
From June 15 through the end of October, the Spokane International Airport received only 1.28 inches of moisture. Based on records since the late 1880s, this was the seventh driest period in recorded history. The normal rainfall at the airport over that 4 1/2-month period is 3.86 inches. In Coeur d’Alene, only 2.08 inches fell during that period compared to a normal 6.63 inches. Prior to June 15, we experienced the second wettest spring ever seen. In this cycle of wide weather extremes, it seems like it’s either feast or famine.
As this new El Niño continues to gain strength, we should see above normal amounts of moisture between now and the first part of December as the storm track will now direct Pacific weather systems directly over our region. This new weather pattern should be a very wet one indeed. Don’t be too surprised to see more precipitation in the next week than the total amount that fell during the past 4 1/2 months combined.
In the lower elevations, most of the moisture should fall as rain through the early part of December with plenty of new snowfall expected in the higher elevations. This is great news for the ski resorts and outdoor enthusiasts. And, I do see at least several periods of snow in the valley floor, with one of them around Veterans Day. I would certainly recommend getting those snow tires on and tuning up those snowblowers.
As we head into December, provided El Niño maintains its intensity, Pacific weather systems should start moving into California as the Inland Northwest typically gets what’s left over as we’re on the northern edge of those storms. At this time, we should turn drier and milder than normal until the early portion of January.
But, I expect January to be the snowiest and coldest of the entire winter season. Don’t be surprised to see more than half of our season’s total snowfall during that month. The normal January snowfall for the Spokane International Airport is 12.9 inches, and we should see nearly 20 inches of the white stuff accumulate during that 31-day period. In the Spokane Valley, up to 25 inches of snow should fall with about 29 inches in Coeur d’Alene. The mountain ski areas may see upward of 80 to 100 inches of the white stuff.
Remember, as mentioned in previous articles, an El Niño pattern does not guarantee a milder weather pattern with less snow, especially in the lower elevations. In 1992-93, another El Niño year, we saw tremendous amounts of snow in Spokane, Spokane Valley, Coeur d’Alene and other areas. It’s happened before and will happen again.