Cold Front Approaches for the Weekend Savannah Tennyson CHEYENNE, Wyo. (Wyoming News Now) - Merry Christmas! Tonight temperatures will be rather chilly so make sure to bundle up if you are headed outside tonight or in the morning. Cheyenne will bottom out at 28 degrees with mostly cloudy skies. Casper bottoms out at 28 degrees with mostly clear skies. High Wind Warnings are in effect for parts of Carbon, Albany, Platte, and Laramie Counties until Saturday at 11am. This is due to winds being sustained at 35mph+ with gusts as high as 70mph. A Winter Weather Advisory is in effect for Yellowstone until Sunday at 6am. A Winter Storm Warning is also in effect for for Fremont, Gallatin, Park, and Teton Counties until Sunday at 6am. Make sure to check the roads for any closures before traveling!