Surprise swirly storm spawns significant snow surrounding Spokane

Heavy snow fell unexpectedly over portions of the Inland Northwest late Thursday, making for a slippery morning commute in some locations.

The National Weather Service received reports of 6.8 inches of snow falling near Hayden and 5 inches in Coeur d’Alene. One member of the public sent the weather service a report of more than 9 inches at U.S. Route 95 and Prairie Avenue between Coeur d’Alene and Hayden.

Significant amounts also fell in some parts of the Palouse north of Pullman, said Steven Van Horn, a National Weather Service meteorologist in Spokane.

The snowfall in central Spokane was significantly less, but still enough to cover the grass – though it didn’t stick on many roads.

Still, the 1.5 inches measured at Spokane International Airport was enough to break the daily record for snow on April 14 of 0.5 inches set in 1955. (The most snow that ever has fallen on any April day in Spokane is 3.8 inches on April 8, 1933.)

The wildly different amounts seen in areas around Spokane, Coeur d’Alene and the Palouse were caused by a “swirl,” Van Horn said.

A swirl occurs when a small area of low pressure develops in the atmosphere and causes a storm to rotate in the same area.

“These little circulations do form and can produce pockets of fairly heavy snow,” Van Horn said. “It’s something that the models have a hard time resolving.”

Which is why no one was expecting to wake up to 6.8 inches of snow Friday morning.

A similar system developed earlier in the day Thursday near Wenatchee and dropped 10 to 16 inches of snow in some areas, Van Horn said.

The snow started in Spokane around 7 p.m.

Another round of precipitation is expected Saturday afternoon, but concern about accumulations on the roads is low, Van Horn said. Driving conditions could be poor in the mountain passes of North Idaho.

The weather is expected to be dry and partly sunny on Easter Sunday and slightly warmer, in the upper 40s.