Areas of freezing fog, sub-zero wind chills

High pressure over the Northwest will usher back the inversion, with freezing fog. Cold air will also be moving south from Canada this week, keeping our daytime highs into the 20's.

OVERNIGHT: Areas of freezing fog with partly to mostly cloudy skies. Lows around 5°, with sub-zero wind chills, SW winds 5-10 MPH. Snow flurries from the fog and low cloud cover.

WEDNESDAY: Freezing fog in the morning with mostly cloudy skies in the Snake River Plain for the afternoon. Highs into the lower 20's with winds at 5-10 MPH.

THURSDAY: Partly sunny with highs into the lower to mid 20's.

AIR STAGNATION ADVISORY IN EFFECT FROM 5 AM THURSDAY TO 11 AM MST SUNDAY:

• WHAT…An extended period of stagnant air, with light winds and little vertical mixing, is expected expected.
• WHERE…Shoup, Bannock Pass, Highway 28 Tendoy to Lone Pine, Highway 93 Lost Trail Pass to Gibbonsville, Lemhi Pass, and Salmon.
• WHEN…From 5 AM Thursday to 11 AM MST Sunday.
• IMPACTS…Periods of air stagnation can lead to the buildup of pollutants near the surface.