Forecast low near 20 by dawn Saturday
Wind, blowing dust in the Columbia Basin and potentially damaging cold are expected Friday across the Inland Northwest as a polar front sweeps into the region and hangs around through Monday, the National Weather Service said.
Gusty winds Friday are likely to be followed by record lows in the upper teens and lower 20s Friday and Saturday nights.
Highs Friday may only reach the lower to middle 40s in a cool-down that will arrive behind the cold front, which would set records for the coldest maximum temperatures for the day.
“The cold air is just going to gradually deepen,” said forecaster Kerry Jones.
A change in weather Monday night and Tuesday could bring a possibility of an early snow as a moist and milder system moves in from the Pacific Ocean on top of the cold air on the ground, forecasters said.
Today the weather service issued a hazardous weather outlook for winds today and freezing weather through Sunday; a dust storm warning for the upper Columbia Basin through 11 a.m.; a blowing dust advisory for south-central Washington from Ellensburg to Walla Walla through 2 p.m.; and a winter weather advisory for the central Idaho Panhandle mountains and western Montana through 7 p.m.
A freeze warning was in effect as well.
Snow has already fallen this week at the region’s ski resorts, including Silver Mountain east of Coeur d’Alene, Schweitzer near Sandpoint and 49 Degrees North near Chewelah.
Forecasters said wind speeds were likely to stay below the levels seen last Sunday, when a section of Interstate 90 west of Ritzville was closed most of the day due to blowing dust.
The cold front is expected to reach a line from Coeur d’Alene to Ritzville and Moses Lake about 2 a.m. Friday.
Record lows Friday night could reach 19 or 20 degrees in the Spokane and Coeur d’Alene areas, with the coldest temperatures coming just before dawn on Saturday. A reinforcing front later on Saturday will keep the cold air in place through Sunday into Monday.
In Spokane, the forecast for Friday calls for a high of 43. The record low maximum is 45 for the day. Early Saturday, the forecasted low of 19 would break the previous record of 25. That pattern should repeat itself for Saturday and Saturday night.
The cold weather could be trouble for sprinkler systems that have not been drained or blown out. Especially vulnerable is the pressure vacuum breaker at the front end of the system that works as an anti-siphon, said Jack Bornstein at Auto Rain, 110 E. Pacific Ave.
He recommended that homeowners insulate the breaker during the freezing weather if the system is still filled with water. Other valves and pipes should be able to withstand the October cold, but will need to be drained or blown out prior to colder winter weather, he said.