After a couple mild days, winter will return to Star Valley later Thursday through the weekend.  A strong cold front followed by a cold upper low pressure trough will move across the region later Thursday and Friday. 

Following is a link to a video presentation from Riverton Forecast Office focusing on the approaching storm

http://www.crh.noaa.gov/riw/?n=weatherbriefing

The following sequence of 500mb forecast charts show the dramatic change in pattern across the western U.S.

Wednesday Evening

Thursday evening

Friday Evening

Saturday Evenig