The Great Plains could also see possible flooding from severe storms on Sunday. A flash flooding risk of a level 2 out of 4 has been issued for central Texas and south-central Oklahoma, with heaviest showers and thunderstorms forecast for Sunday evenings, including the Texas cities of Abilene, Wichita Falls and parts of Fort Worth.

Smoke from wildfires blazing across Canada is once again wafting over huge portions of the U.S. Midwest and worsening air quality there. On August 1 conditions are particularly bad in Minnesota, Iowa and Illinois.

Health officials from Minnesota to Maine have issued alerts warning of poor air quality from wildfires burning in Canada. People are advised to limit outdoor exposure.