Wintry weather conditions are expected to move into the Inland Northwest this week under a northerly flow out of Canada.
“The trend is for much colder temperatures,” said meteorologist John Livingston at the National Weather Service in Spokane.
Highs by Sunday could only reach the low to middle 20s, although even colder weather is possible, he said.
In addition, light snow or rain is possible on Thursday night and Friday as a weak weather disturbance moves southward from Canada. The forecast this afternoon placed the chance of precipitation at 30 percent in Spokane on Friday.
A strong ridge of higher air pressure has formed along the West Coast extending northward into British Columbia, creating an upper flow of air from north to south over the Inland Northwest, Livingston said.
Initially, the high pressure provided fair weather to the region Sunday and early today, but clouds have moved into the region this afternoon. The low clouds and fog are possible at times through midday Thursday from a cold-air inversion.
The region should see sunny weather on Tuesday and Wednesday as the northerly flow clears out the low-lying clouds and fog.
Highs are forecast to drop to the 30s through Saturday with lows at night in the 20s.
A weak system Thursday night and Friday will initially allow temperatures to moderate upward by a few degrees before a shot of Canadian cold moves southward on Saturday, Livingston said.
The cold could hang around until the middle of next week, he said.
Normal temperatures in Spokane for this time of year are 35 for a high and 25 for a low.