Heat dome pushes triple-digit temperatures westward, raising wildfire and smoke risks

A high-pressure system described as a heat dome will move westward across the United States later this week, bringing triple-digit temperatures to the Southwest and interior California. Senior AccuWeather meteorologist Chad Merrill said the dome will push from the Texas Panhandle into the Southwest, with highs of 100-111 °F expected in Oklahoma and Texas and 110-120 °F in California’s desert areas.

The heat dome acts like a lid on the atmosphere, trapping heat and dry air, which meteorologists say raises the risk of wildfires and deteriorates air quality. Merrill warned that wildfire danger will be very high east of the Cascades in Washington and Oregon, as well as in British Columbia, the Sierra Nevada, the Great Basin, southern California’s mountains and the northern Rockies. He added that strong winds could carry fires into Idaho and Montana over the weekend.

According to AccuWeather, smoke from these fires is likely to be most severe in the Northwest and could extend into the Dakotas and the Northeast later in August. While recent rain in Ontario, Canada, has temporarily eased smoke in the Northeast, the forecast jet-stream pattern suggests smoke will continue to move across the region.

The National Weather Service’s Weather Prediction Center projects that high pressure will keep temperatures well above normal across the Plains, Mississippi Valley and Southeast, with afternoon highs reaching the upper 90s to low 100s, and some Desert Southwest locations potentially hitting 115-120 °F.

Health officials, including the Centers for Disease Control and Prevention, advise the public to watch for signs of heat-related illness such as heat stroke and heat exhaustion.