The icy coating breaking trees and dropping power lines is supposed to start melting today.
“Trees will be throwing ice balls at people,” said Paul Frisbie, National Weather Service forecaster in Spokane.
Forecasters are calling for a high of 35 degrees with occasional sunshine as Tuesday’s punishing storm saunters out of the region.
A chance of snow showers remains in the forecast, but mostly over the mountains.
While freezing rain is not unusual in the Spokane region, the amount that fell Tuesday was much heavier than ice storms in past years.
Rain coated snowy tree branches and power lines, quickly turning into ice. Tree limbs snapped like kindling under the sheer weight of the ice.
Autumn leaves or seed pods still hanging from the branches added more surface area for snow and ice, increasing the weight.
For Spokane, the rain was heavy by any measure.
About an inch of precipitation fell Tuesday, first as snow, then as freezing rain. About 3 inches of snow fell at the Weather Service station near Airway Heights before it changed to freezing rain about 8 a.m.
The freezing rain was caused by mild wet air in the upper atmosphere, and cold air at the ground.
At midday Tuesday, the Weather Service measured freezing temperatures from the ground to about 1,000 feet in the air, or an elevation of 3,100 feet above sea level.
From there, the air temperature was above freezing to an elevation of 8,200 feet above sea level. That mile-deep gap of mild air caused the precipitation to fall as rain, and stick to ice-cold trees and power lines.
Rain was reported south of an arching line that ran from Davenport in Lincoln County, to Deer Park in Spokane County to Metaline in Pend Oreille County to Athol in North Idaho. Snow fell to the north of that line.
Frisbie said an elongated low pressure area pushed wet mild air off the Oregon coast into the upper levels of the atmosphere over Spokane and North Idaho.
The center of low pressure passed to the south of Spokane, drawing cold air along the ground from an Arctic high pressure area to the north.
The shallow layer of cold seeped down the valley running from Bonners Ferry to Sandpoint into the Rathdrum Prairie, and then spilled west into Spokane and southeast into Coeur d’Alene. A blizzard was reported north of Athol.
In Spokane and Coeur d’Alene, cold air hugged the ground and kept temperatures below freezing.