Heat wave triggers big storms, power outages in US Southeast, raises wildfire concerns in Southwest

Triple-digit temperatures have prompted severe weather and another round of heat advisories across much of the southern United States. The unstable conditions triggered thunderstorms that knocked out power to hundreds of thousands of people from Oklahoma to Mississippi. It's also producing gusty winds in the Southwest that raised wildfire threats in Arizona and New Mexico. A suspected tornado struck near Scranton, Arkansas early Sunday, destroying chicken houses and toppling trees onto houses. There were no immediate reports of serious injuries. Reports Sunday indicated more than 740,000 people were without power in Oklahoma, Texas, Louisiana, Arkansas, and Mississippi. Louisiana Gov. John Bel Edwards declared a partial state of emergency on Saturday.