Western heat dome fuels growing wildfire, flood threats
A dangerous heat dome will push Southwest temperatures near 120 this weekend as wildfire danger surges in the Northwest and sporadic thunderstorms threaten flash flooding from the Rockies to the Great Basin and deserts.
Bernie Rayno breaks down what heat domes are and when the highest temperatures are expected in the Southwest.
The latest in a series of dangerous extreme-heat domes in the United States this year will peak over the Southwest this weekend, accompanied by spotty thunderstorms. At the same time, an incoming Pacific storm threatens to heighten wildfire risks in the Northwest.
Heat domes affected the West in February and March before developing across the Central and Eastern states later in the spring and summer.
Temperatures above 100 degrees Fahrenheit are common in the deserts during midsummer. However, this strengthening heat dome will push highs 10-20 degrees above the historical average into early August.
Palm Springs, California, could hit 120 degrees on Saturday. While the city has reached or exceeded that mark in past years, many summers fall short of it. Temperatures this extreme are dangerous even by desert standards and can quickly lead to heat-related illness or death without proper precautions.
Temperatures will surge into the 90s in downtown Los Angeles for several days, while neighborhoods east of downtown could approach 100 on Saturday. Note that the 98-degree reading in downtown Los Angeles during a March 17 heat wave has yet to be topped.
Phoenix will come within a few degrees of 115 each afternoon through Sunday.
Daily record highs will be challenged throughout the interior Southwest through the weekend.
People are urged to take frequent breaks, stay hydrated and limit alcohol and excessive caffeine, both of which can accelerate dehydration.
Beachgoers in Southern California should remain alert for dangerous surf, strong rip currents and sneaker waves as swells from Tropical Storm Genevieve arrive from the eastern Pacific. Swells can remain active even as storm wind intensity diminishes.
Anyone escaping to the mountains should watch for rapidly developing thunderstorms that can produce frequent lightning over exposed ridges and flash flooding in nearby canyons, arroyos and valleys.
The combination of extreme heat in the Southwest and strengthening winds in the Northwest will elevate wildfire danger to extreme levels this weekend.
Vegetation that flourished after winter storms has dried dramatically during the first half of summer and can now ignite easily. Extreme caution is urged with open flames and power equipment that can produce sparks. Even driving a vehicle over high brush can ignite a blaze from a hot exhaust system.
As winds strengthen in the Northwest on Saturday then spread across the interior West on Sunday, the risk of erratic, fast-moving wildfires will increase dramatically. Existing contained fires could jump control lines under the conditions and put firefighters at risk.
This photo provided by the Oregon Department of Transportation on Monday, July 27, 2026, shows the Fox Fire burning in eastern Oregon. (Oregon Department of Transportation via AP)
Smoke from ongoing and new wildfires will create unhealthy to dangerous air quality across parts of the West.
Farther downwind, smoke will remain mostly aloft over portions of the Midwest and East into next week, creating a hazy sky and colorful sunrises and sunsets.
As the Pacific storm moves inland across British Columbia and the Northwest early next week, temperatures will ease across much of the West. However, dangerous heat is expected to linger from interior Southern California into Texas.
Young children and the elderly are more sensitive to extreme heat. Temperatures can reach lethal levels in a vehicle in a matter of minutes for young children and pets. Consider bringing pets indoors during heat waves to help keep them cool and hydrated.
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