Triple-Digit Heat and 120-Degree Highs Are Coming for the Southwest

A long-lasting heat dome is forecast to set up across the Southwest into next week, ushering in dangerous triple-digit temperatures along with an elevated wildfire risk. Here is a look at when and where you should expect this extreme heat to take hold.

Los Angeles, San Diego, Las Vegas, and Phoenix Forecast to Sizzle

Once again, a powerful heat dome is going to tether itself to the Desert Southwest, resulting in life-threatening temperatures for millions. The large area of high pressure that is currently bringing toasty conditions to the Great Plains this week is forecast to move to the southwest beginning on Friday. The center of this zone of high pressure will settle over the Arizona and Utah border. The western fringe of this heat dome will reach as far as Southern California.

Some of the heat will creep as far as the Los Angeles basin and San Diego, thanks to an offshore breeze coming from the interior Southwest and traveling toward the Pacific coastline. The extreme heat will not be the only hazard in this part of the country. Large swells generated from the former Category 5 Hurricane Genevieve will create strong rip currents and the threat of sneaker waves along the beaches in Southern California, just as people are diving in to escape the heat.

The forecast is calling for the mercury to soar into the mid to upper 90s for most of Southern California, including the Los Angeles metro area. Temperatures will easily surpass the century mark in areas to the east. The desert resort town of Palm Springs is bracing for highs that approach the 120-degree mark.

The Desert Southwest will sizzle with temperatures hovering between 110 and 120 degrees in Las Vegas and Phoenix. Neither of these cities is a stranger to the heat, but this is hot by even their standards.

The power of the high pressure within the heat dome will also work to temporarily put a lid on monsoonal activity in the Southwest. Any thunderstorms that do ignite will likely remain over the higher elevations.

Lastly, a storm system dipping down into the Pacific Northwest will produce higher winds across some areas of the West. The merger of the heat, intense sunshine, and gusty conditions will naturally raise the risk of wildfires up and down the West Coast.

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