People in parts of Colorado and Wyoming pulled puffy jackets, hats and umbrellas out of the closet again Wednesday for another round of wet spring snow. The May Day snow storm was making travel difficult on some Colorado highways, where several crashes were reported late Wednesday, and along Interstate 80 in southeastern Wyoming. Denver's airport reported about 50 flight cancellations, and other flights were delayed for de-icing.

© AP Photo/The Argus Leader, Dalton WalkerArvid Buseman clears snow off his car Wednesday morning, May 1, 2013 in central Sioux Falls, S.D. Sioux Falls, South Dakota's largest city, got its first May snowfall in 37 years Wednesday and its largest May amount since 1944.
By midday, more than a foot of snow had fallen at Rocky Mountain National Park. The heavy snow caused power and heat outages there and in Cheyenne, which received 15 inches of snow by noon Wednesday. West of Cheyenne, 20 inches fell near Buford, while Casper saw 4 inches of snow. Parts of the Midwest were also getting rare May snow.
South Dakota's largest city, Sioux Falls, got its first May snowfall in 37 years. The city received 1.5 inches of snow by late morning. A winter storm warning was also in effect for parts of Minnesota and Wisconsin. Snow fell in parts of Nebraska, and western Iowa was expecting snow between Wednesday night and Thursday morning.