Winter weather advisory for snow in the Columbia Basin on Sunday

A low pressure system slowly moving offshore is forecast to spin moisture into the Columbia Basin Sunday as it meanders closer to the Southern Oregon Coast. This has prompted the National Weather Service to issue a winter weather advisory for the Tri-Cities, Walla Walla, Hermiston, and surrounding areas in effect from 04:00 to 22:00 Sunday.

The advisory calls for 1-3 inches of snow during this time period, though there is still a modest amount of uncertainty regarding exact totals. Modeling suggests that a band of moderate snowfall somewhere in the range of 20-40 miles wide may park within the advisory area for a few hours, giving that lucky group snowfall totals toward the higher end of (or a little above) what is given in the advisory from the National Weather Service.

Light snow is forecast to continue into the overnight hours, but the bulk of the precipitation is likely to be closer to Moses Lake and Ritzville. Still, an additional inch is possible between when the advisory ends and sunrise on Monday.

With temperatures having been below freezing for a while now and not likely to break above freezing until Tuesday or Wednesday, falling snow will have no problem sticking. Use caution while driving, especially on bridges and overpasses. Rough driving conditions continue later into the day north of the Tri-Cities.

Mostly cloudy skies and cold temperatures are forecast after the snow ends, lasting until at least midweek. The next shot of precipitation comes Thursday, but the chance is low at this time.