Strong-to-severe storms will move across sections of the central U.S. and over the Ohio and Tennessee River Valleys on Wednesday.
Large hail, damaging winds, tornadoes and heavy rain could lead to flash flooding in these areas.
This comes as the heat is still breaking records for the Southern Tier of the U.S., where warnings remain from Texas to Florida.
Monsoonal rainfall along with remnants of a tropical system in the Pacific will bring some much-needed moisture to the Southwest on Thursday.
Meanwhile, Hurricane Dora is a powerful major hurricane south and west of Hawaii.