The difference between blizzard-like and actual blizzard conditions should become apparent Friday, when the National Weather Service predicts the real thing will blow all over the U.S. Highway 93 corridor.
“This storm has been in the models for about 10 days, and it’s been remarkable to watch the evolution,” NWS meteorologist Corby Dickerson said Thursday. “It will (be underway early Friday morning) and continue, if not get worse, on Saturday morning.”
“It” is snow with strong winds that should cause whiteout conditions in the East Missoula/Bonner area, through the Hellgate Canyon and into downtown Missoula on Friday morning. To qualify as a blizzard, it must have sustained winds or frequent gusts of 35 mph or more reducing visibility to a quarter-mile or less for at least three hours. Friday qualifies.
“It’s going to be downright impossible to go anywhere,” Dickerson said. “This will be a true blizzard, which will significantly affect much of Missoula, the northern Flathead and travel corridors across the Continental Divide. Driveways and walkways and other pathways will become drifted over, and whiteout conditions will be commonplace for a good period of time.”
The blizzard warning also extends through the Bitterroot Valley south to Darby and Lost Trail Pass. Most of the Highway 93 north-south corridor received freezing rain Thursday afternoon, which was expected to transition to snow and howling wind about 2 a.m. Friday.
At higher elevations, the freezing rain already had switched to heavy snow by Thursday afternoon, which could create problems of its own.
“The warm weather we had (Wednesday) left a sun crust on the snow,” said Steve Karkanen of the West Central Montana Avalanche Center. “What we’re concerned about is how this new snow will bond to that surface. If we get this big storm, especially the high winds, its definitely going to increase avalanche danger.”
The coming storm prompted Missoula County Public Schools officials to cancel basketball games at Sentinel, Hellgate and Big Sky high schools Thursday evening. MCPS spokeswoman Hatton Littman said the school district would make calls about any late starts or cancellations for Friday.
“Keep an eye on our Facebook and web pages,” she said. “Weekend games will also be affected.” Any cancellations or delays also will be on Missoulian.com and on the Missoulian’s Facebook page.
Snowfall between 5 and 7 inches should start falling before dawn Friday in the Missoula Valley. The winds should arrive just as everyone’s heading for work, with sustained blows of 40 to 50 mph and gusts up to 60 mph forecast. That could drive wind-chill effects into the minus 20 to minus 40 degree range.
The snow should abate as Friday wears on, but the winds should keep coming from the east at about 20 mph. Another punch of arctic air should flow across the Continental Divide into the Missoula area late Friday afternoon, about the time everybody’s heading home.
Dickerson said those winds should get stronger overnight, with Saturday expected to have a low temperature around zero and struggle to reach the lower teens for a high. The air should stay breezy all day.
By Sunday, the cold should be settled in tight, with a low of around minus 5 degrees. However, another moist weather system from the Pacific Coast is expected to arrive sometime Sunday evening or early Monday. Details of that storm are still under analysis.
Not everyone was taking the storm news as bad, however.
“For those of us who recreate in the backcountry, this is great,” Karkanen said. “This is what we live for.”