By Nic Loyd, WSU meteorologist, and Linda Weiford, WSU News
– Above average cold
– Above average snowfall and winds
– An ice storm
– A rapid and drastic shift from freeze to thaw
– Rain, more wind and a slushy, watery mess
– Dense fog
Consequently, we encountered waist-high snow berms, icy roads, highway closures, flight cancellations, canceled classes, clogged storm drains and localized flooding. It has been a weird, challenging winter and, amazingly, it’s not even half over.
A combination of powerful climatic forces has helped create this odd winter spectacle. La Nina is among the big-name performers partly to blame – or credit – for the waves of subzero weather and snowfall that walloped central and eastern Washington in December and the first part of January.
La Nina’s flipside is El Nino, and you may recall that in 2015 it was largely to blame for unusually warm weather and a lack of mountain snowpack that caused serious drought conditions. With a swing of a global climatic pendulum, a La Nina pattern followed and did just the opposite, bringing colder temperatures and more snowfall this winter.
While disturbingly cold, the upside is that a drought-stricken Pacific Northwest got blasted with snow in the mountains and lowlands alike. Skiers have celebrated dry powder not seen in some time.
Then suddenly, a switch got flipped. Last week, temperatures soared, rain fell and a thawing wind arrived. Jostling La Nina was a strong atmospheric river that took aim at the Pacific Northwest. Unlike the three severe, freezing weather systems that had earlier descended from western Canada, this was a 3,500-mile-long plume of warm, wet and windy air that formed over the subtropical Pacific Ocean.
Now, after about a week of relatively mild weather conditions, another climatic event has descended upon us: Fog.
A ridge of high pressure has parked itself over the region, creating a temperature inversion that’s bringing rounds of fog and freezing fog into this weekend. When water droplets in fog freeze onto highways, it creates a layer of ice. In other words, take your time driving.
And remember, spring is two months away.
Weathercatch is a bimonthly column that appears in The Spokesman Review. Nic Loyd is a meteorologist with Washington State University’s AgWeatherNet. Linda Weiford is a WSU news writer and weather geek. Contact: firstname.lastname@example.org.