The zone of wintry precipitation will follow an outbreak of cold air and rounds of heavy snow from the interior Northwest to the northern Rockies and northern Plains. Following a storm earlier in the week that unleashed cold air and snow across the northern Plains, the ingredients for yet another storm began to come together at the end of the week.A plunge in the jet stream over the West has allowed cold air to blast across the Colorado Rockies at the start of the weekend. From the High Plains of northeastern Colorado and southeastern Wyoming to southern Minnesota and northern Wisconsin, a late-October chill will set in into Sunday.