Arctic cold brushes region, clears skies

A glancing shot of modified arctic has moved across the Inland Northwest this morning, and forecasters said it is having the effect of clearing out any threat of snow through the weekend. Fog may be a problem starting late Friday. Sun and a high of about 30 are expected today with lows tonight in the teens. The sun returns on Thursday and Friday with highs in the middle to upper 20s and lows in the teens. High pressure is expected to move across the region and bring the clear skies initially, but as a low-lying layer of cold air becomes saturated with moisture there will be a risk of freezing fog starting Friday night. The coldest arctic air should move east of the Continental Divide by Thursday, leaving the Inland Northwest under a system of higher air pressure off the Pacific coast. A low-level temperature inversion with cold air stuck beneath warmer air aloft is common under high pressure systems during the Inland Northwest winter. Inversions are typically accompanied by fog, low clouds and stagnant air. Pollution levels may rise by this weekend. The pattern is called an inversion because air normally gets colder with a rise in elevation. Cloudy skies are likely from Sunday through Tuesday as temperatures moderate by about 5 to 10 degrees with highs near 30 and lows in the 20s. At 8 a.m., it was 24 at Spokane International Airport, 27 in downtown Spokane, 19 in Coeur d’Alene, 21 in Deer Park and 28 in Pullman.