Your weather word for today: Snownado

We’ve all seen videos of tornadoes and dust devils that have swirling winds. However, there's a very rare phenomenon that occurs when there are swirling winds over snow, looking like a small tornado or dust devil.

For this to occur, the ingredients and conditions have to be just right to generate a “snownado,” which is sometimes called a “Snow Devil.”

This phenomenon usually behaves more like a dust devil. Many of us have probably seen these rotating columns of wind and dust that almost look like a mini-tornado, especially in desert or dry regions. Dust devils are mostly composed of dust and other particles that could literally cause damage to your car or structure.

Snownadoes are generally small, but according to an article on Science Explorer, some have been reported as large as 30 feet wide and 45 feet high. Although they are much less intense than tornadoes, it was reported snownadoes that size are capable of lifting objects weighing over 1,500 pounds. Because highly destructive tornadoes need warm and humid air near the surface, snownadoes are too cold to produce that kind of force.

Snownadoes have also formed over water, mainly frozen lakes or snow-covered areas. As a result, most of them have been reported in Canada. Until recently, it was rare for a snownado to be caught on camera. But, thanks to the increased number of cell phones, there has been a recent increase of snownadoes caught on video.

For these events to occur, very specific conditions are required. There needs to be a colder air mass that passes over a warmer surface that is heated by the sun. This can create a wind shear as the colliding cold and warmer air start to create a spinning effect as the warmer air rises and sometimes rotate, creating the rare “snownado.”

Last week, a rare and heavy snowfall event was reported across Turkey and Greece, resulting in power outages and clogged roads. Heavy snow was seen in Athens, only its sixth snow event since 2000.

The storm was strong enough that a snownado formed from a waterspout, essentially a tornado on water, and moved across the land in Greece. The event made international news because it was so rare, especially in that part of the world.

Cliff and I could not find any reports of a snownado across the Inland Northwest. However, one was photographed on Sun Valley’s Bald Mountain on Jan. 26, 2018. In the past several years, Colorado residents and visitors have also reported seeing this phenomenon.

In terms of our local weather, from Jan. 6 through 30, about an inch of snow fell in Coeur d’Alene. According to Cliff’s records this was the most snowless period in recorded history. A new storm arrived over the weekend, but moisture amounts were very low.

As we move into February, it will start out with more chilly temperatures with occasional snow in Coeur d’Alene and the rest of the Inland Empire. The upper-level wind flow patterns are directing these storms from a more northerly direction, so snowfall totals are not expected to be high.

The chances are still good for additional snowfall into the late winter and early spring season as we continue to have a light to moderate La Nina, cooler-than-normal sea-surface temperature pattern in the waters of the south-central Pacific Ocean. As we’ve stated previously, during La Nina years, the northwestern portion of the country will often see above-normal snowfalls.

So far, Cliff has measured approximately 50.5 inches of snow at his station in northwestern Coeur d’Alene. At Spokane International Airport, about 30 inches of snow has fallen for the season, slightly less than normal.

Our original snowfall projection for the 2021-22 season was 83.4 inches. There’s still a chance we’ll get close to that figure before the season ends, but it’s becoming more obvious that the first half of the winter season will likely be snowier than the second half.

Assuming weather patterns continue to be influenced by La Nina into the spring season, conditions across the Inland Northwest may be a little cooler and wetter than average. However, areas to the south, especially in California, are expected to turn to the dry side once again.

Over the last 10 years, Coeur d’Alene and surrounding regions have mostly experienced wetter-than-normal winter seasons with very dry summers. Based on the current and projected weather patterns and trends, the chances are higher than average for another dry summer season.

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Contact Randy Mann at randy@longrangeweather.com