Weathercatch: A storm out of season jolts the region after record warmth. Will Halloween temperatures be more seasonal?
With Halloween just four days away, not only is the first frost on the pumpkin, but also the first snow.
An abrupt change in the weather pattern this week left a big chill and a trim of white on jack-o’-lanterns and autumn leaves, all of which feels a little jarring. After all, a week ago, the warmth and widespread sunshine was reminiscent of the Fourth of July. On Oct. 19, Spokane basked in a daily record high of 76 degrees. Today we’ll be lucky to reach 40. To put that in perspective, the normal high for today is 55.
How did we get so quickly from uncommonly warm to unseasonably cold?
The change was mostly driven by the convergence of two systems: a cold, very moist air mass from the North Pacific and a frigid air mass that spilled south from the northern tier of Canada.
The result was a “long duration winter storm,” according to the National Weather Service, that bore down on the Pacific Northwest and Northern Rockies beginning on Tuesday. Snow arrived in the Cascade Range early Tuesday afternoon and spread across the Inland Northwest through Wednesday. How long it snowed and how much varied significantly by location. Helena, Montana, received a foot, and Stevens Pass got 7 inches. Spokane International Airport and Sandpoint picked up a little over 1 inch, and Pullman saw a mix of rain and snow.
Meanwhile, as snow flurries subsided, temperatures continued to drop. Residents of the Inland Northwest awoke Thursday morning to the region’s first widespread freeze. The surge of chilly air is expected to bring overnight lows into the low 20s and even the teens through this weekend. The last time Spokane experienced temperatures this cold was on March 1.
If nature stops playing tricks, conditions should creep closer to normal by Halloween on Tuesday. For now, Oct. 31 is looking to be mostly sunny, with highs in the upper 40s and lows around 28.
Nic Loyd is a meteorologist in Washington state. Linda Weiford is a writer in Moscow, Idaho, who’s also a weather geek.