After this weekend's cold front, cold air is spilling into the region. We'll look for single digit and sub-zero low temperatures Monday night and Tuesday morning.
The National Weather Service in Pocatello, has issued a WIND CHILL WARNING for Clark, Fremont and Teton counties in Eastern Idaho. Wind chill values could drop as low as -30°, with north winds 10 to 15 mph, with gusts as high as 25 mph.
"Arctic air has spilled over the continental divide from southwest
Montana. The air is extremely cold, with single digit overnight
lows expected as far south and west as the eastern Magic Valley.
Widespread areas of Clark and Fremont counties will also have
enough wind to plunge Effective Chill Temperatures (Windchill)
below minus twenty degrees Fahrenheit. In addition, the cold air
will act as a small cold front once it reaches the American Falls
Reservoir. It will spread light to moderate snow from areas west
of Pocatello all the way to Burley tonight.
Upper Snake Highlands-
Including the cities of St. Anthony, Ashton, Driggs, and Victor
1232 PM MST Mon Feb 19 2018
...WIND CHILL WARNING IN EFFECT FROM 6 PM THIS EVENING TO 10 AM
* WHAT...Dangerously cold wind chills will cause frostbite in as
little as 10 minutes to exposed skin. Expect wind chills to
range from 20 below zero to 35 below zero.
* WHERE...The upper Snake Highlands, including Clark and Fremont
counties in Idaho, including the towns of Macks Inn, Island
Park, Dubois, and Spencer.
* WHEN...From 6 PM this evening to 10 AM MST Tuesday. At first,
elevations at or above 7000 ft will be affected, then by
midnight this should spread down in elevation until nearly all
of Clark and most of Fremont counties are affected.
* ADDITIONAL DETAILS...The windchill is caused by air temperatures
below zero combining with wind of 10 to 15 mph.
A Wind Chill Warning means the combination of very cold air and
the wind will create dangerously low wind chill values. Frost
bite can occur quickly and even hypothermia or death if
precautions are not taken."