Roughly 130 million people in 22 states are under various heat warnings, watches and advisories as a dangerous heat dome settles over a huge section of the county. The searing August heat wave is forecast to continue through at least the end of this week. The National Weather Service says a potent upper-level ridge is anchored over the Mid-Mississippi Valley, trapping the hot air. It is bringing oppressive heat from the central U.S. to the Gulf Coast. High temperatures throughout these areas are forecast to reach into the upper 90s and low 100s through Thursday.