Slightly cooler temps, scattered showers and storms expected Saturday in Wyoming By Greg Hirst on May 1, 2021 File Photo (Trevor T. Trujillo) CASPER, Wyo — Scattered showers and thunderstorms are expected in afternoon in parts of central and western Wyoming Saturday, with temperatures slightly cooler than the record-breaking heat Friday, according to the National Weather Service (NWS) in Riverton. NWS Riverton Casper is looking at a high of with a high near 75 and light breezes up to 11 mph. Cloud cover will increase throughout the day, with a chance of isolated showers and thunderstorms after 3:00 pm. Increasing clouds. The chance of showers increases to 50% after midnight.