Strong winds and dry thunderstorms are raising the risk of fast-moving wildfires across much of the U.S. West, where forecasters warned conditions will favor new ignitions and rapid fire spread through Thursday.
An elevated fire-weather outlook, Level 1 on the Storm Prediction Center’s three-tier scale, is in effect from California’s Sierra Nevada to western Colorado. Red flag warnings have also been issued for parts of Washington, Idaho and Utah.
Thunderstorms are expected from Idaho south into northern Arizona and New Mexico, according to Nick Nauslar, a fire science and operations officer at the Storm Prediction Center. Some of these will contain rain, but many will not, raising the risk of dry lightning in the area.
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While the pockets of rain will help the areas where they fall, much of the area vegetation remains dry and ready to burn, Nauslar wrote, “including record dry fuels in portions of Utah and Colorado.”
Dry lightning occurs when the air is so parched that rain actually evaporates before it can hit the ground. All that’s left is the lightning bolts that can spark fires and have been the cause of massive blazes in the past.
The elevated fire risks will continue Thursday mainly across Southern California to western Colorado and New Mexico, the agency said.
Elsewhere, excessive heat will persist across parts of Southern California and the Southwest, as well as portions of coastal North Carolina, South Carolina, Georgia and Florida.
Air quality alerts are also in effect along the southeastern shore of Lake Michigan because of elevated ground-level ozone.