Be ready for some potentially slick roads during Tuesday morning’s commute.
The National Weather Service issued an overnight winter weather advisory for the Tri-Cities as a Pacific weather system moved into the Mid-Columbia late Monday afternoon.
The advisory started at 4 p.m. Monday and was expected to end at 4 a.m. Tuesday.
Monday night Alaska Airlines had canceled two flights from Seattle and one from Portland that had been set to arrive at the Tri-Cities Airport between 9:45 p.m. and 12:03 a.m. Some outbound flights also were canceled for Tuesday morning.
A deep layer of cold air is trapped over the Lower Columbia Basin and the east slopes of the Washington Cascade Mountains, according to the weather service. It may cause snow to fall in some higher elevations and sleet at lower elevations as the storm moves across the Mid-Columbia.
The Tri-Cities was expected to have rain Monday evening, possibly mixing with freezing rain and sleet overnight. The chance of precipitation was 100 percent, according to the weather service.
Little or no sleet accumulation was expected, but there was a possibility of about a tenth of an inch of ice to accumulate on the ground in the Tri-Cities, according to the weather service.
Check bit.ly/snowdelays for any school delays.
Storm drains may not keep up with the combination of rain and melting snow, according to the weather service. There also may be some flooding of small streams, but the Yakima River is not expected to rise significantly.
Temperatures are warming up this week in the Tri-Cities.
Tuesday the high could be as warm as 48 after an overnight low that may have been just above freezing, said the weather service.
Winter breezes may make the temperature feel colder than it is. Tuesday the wind is expected to pick up from 14 to 19 mph early in the morning to 20 to 25 mph before noon. Gusts of up to 39 mph are expected.
The air quality also had deteriorated Monday in the Tri-Cities.
By late morning Monday, it was rated barely below the classification of “unhealthy for sensitive groups.” At that level, people with heart or lung disease, asthma, diabetes, infants, children, seniors and pregnant women should limit time spent outdoors.
By afternoon, the air quality had improved to “moderate,” and by evening was rated “good.”
Snow levels in the mountains will be dropping as the weather warms. The snow level could be near 5,000 feet early Tuesday along the Cascades before dropping to 3,000 feet by Wednesday, according to the weather service.
In the Blue Mountains, snow could be at 4,000 to 6,000 feet by late Tuesday before decreasing to 3,000 feet by Wednesday morning.
Travelers were having difficulty Monday.
Interstate 90 was closed westbound at Ellensburg for about 40 minutes in the morning because of multiple crashes, and chains were being required at the summit. Traffic also was backed up eastbound because of the weather and spinouts.
More snow is expected Tuesday and Thursday at Snoqualmie Pass, according to the weather service.
Traffic was at a standstill on Interstate 84 near Hood River, Ore., Monday afternoon because of crashes. The Oregon State Patrol said traffic wast backed up for 10 miles.
In the Blue Mountains, snow drifts have closed the Tollgate Highway between Weston and Elgin and Highway 334 between Athena and the junction of Highway 37.