The US National Weather Service on Friday said it expects a heatwave to intensify in the Southwest before peaking and spreading to the Intermountain West and northern High Plains over the weekend.
The agency forecast severe thunderstorms and heavy rain to move from the Plains and Mississippi Valley towards Upper Midwest and mid-Mississippi Valley on Friday and further expects persistent monsoonal showers and flooding in the Desert Southwest.
The NWS early Friday issued an extreme heat warning for St. George, Zion National Park, Escalante, Capitol Reef National Park, Moab, Green River, Ogden, Salt Lake City, Tooele, Provo, Hanksville and parts of Bluff and Blanding. The state primarily falls under the service area of PacifiCorp's Rocky Mountain Power.
A similar warning was raised for Oklahoma's Bartlesville, Tulsa, Muskogee, McAlester, and parts of Oklahoma City. OGE Energy (OGE) subsidiary Oklahoma Gas & Electric and American Electric Power's (AEP) Public Service Co. of Oklahoma are the major service providers in Oklahoma.
Affected areas in Arizona included: Yuma, Parker, Kingman, Bullhead City, Kingman, Ajo, Gila Bend, Phoenix, Wickenburg, Dateland, Prescott, Payson, Globe, Casa Grande, Tucson, Nogales, Sierra Vista, Bisbee, Page, Oracle, Oro Valley, Benson, Safford, Sells, Green Valley, and Grand Canyon Village.
Arizona is primarily served by Pinnacle West Capital (PNW) unit Arizona Public Service Company, and UNS Energy subsidiaries Unisource and Tucson Electric Power.
Also placed under an extreme heat warning watch were Tonopah, Beatty, Las Vegas, and Caliente in Nevada, which falls under the service area of Berkshire Hathaway Energy unit NV Energy.
In California, an extreme heat warning was raised for Blythe, El Centro Imperial, Palm Springs, Twentynine Palms, Barstow, Baker, Death Valley, Barstow, Baker, Death Valley, Tehachapi, Bishop, Campo, El Cajon, Mount Laguna, Julian, Borrego Springs, Indio, Escondido, Temecula, San Clemente, San Bernardino, Hemet, Beaumont, Victorville, Anaheim, Ontario, Chino, Los Angeles, Santa Ana, Burbank, Palmdale, Riverside, Santa Clarita, Long Beach, Oxnard, Malibu, San Luis Obispo, Ridgecrest, Santa Maria, Paso Robles, Frazier Park and Edwards AFB.
PG&E (PCG) subsidiary Pacific Gas and Electric, Edison International's (EIX) Southern California Edison, and Sempra Energy (SRE) unit San Diego Gas & Electric are the major electricity service providers in these places.
Fort Smith in Arkansas was also covered under an extreme heat warning watch.
The NWS issued flood warnings for South Dakota's Chamberlain, Sisseton, and areas near Aberdeen and Mobridge, while a flash flood warning was raised for places near Huron and Brookings. Northwestern Energy (NWE), MDU Resources (MDU) unit Montana-Dakota Utilities and Otter Tail's (OTTR) Otter Tail Power are among the major electric service providers in these places.
Flood warnings were also raised for George West in Texas and Wheaton in Wisconsin.