Risk of heavy rainfall, flash flooding as thunderstorms return to Wyoming By Brendan LaChance on July 27, 2021 A vehicle drives through water covering a section of the frontage road near the Sinclair Refinery in Evansville on Tuesday, May 28, 2019. (Dan Cepeda, Oil City) Showers and thunderstorms are likely in western and central Wyoming every day from Wednesday through Sunday, according to the National Weather Service in Riverton. “The main hazard will be locally very heavy rainfall which could cause some flash flooding,” the NWS in Riverton adds. Article continues below... East central, south central and southeast Wyoming could also see some heavy rainfall with a chance of afternoon and evening thunderstorms Wednesday through the weekend.