HEYENNE, Wyo. (AP) — An Arctic airmass is keeping its grip on much of Wyoming.

Temperatures as low as 20 below and wind chill values of between 20 and 40 degrees below zero are possible Thursday.

Some locations never got above zero at all on Wednesday and some of those sub-zero temperatures set new records — for high temperatures.

The National Weather Service says Buffalo only got up to minus 7 and Casper topped out at minus 5, both new record highs.

Another long-lasting winter storm is expected to hit the western mountains on Friday. Between 6 inches to a foot of snow could fall each day over the weekend.

The cold weather is also expected to moderate this weekend.