US Braces for Extreme Heat Dome

Large swaths of the U.S. are set to experience dangerous heat this weekend and into early next week. A significant heat dome is forming over the interior West, with forecasts predicting triple-digit temperatures.

Initially impacting the interior West, the heat dome is expected to expand into the Midwest and eventually reach parts of the East. The most intense heat is likely to concentrate from the northern Rockies into the Midwest, threatening temperature records from Nevada to Wisconsin. Highs are projected to exceed 100 degrees Fahrenheit in areas like the Great Basin and Intermountain West.

As the heat moves eastward, increased humidity will intensify the feeling of heat across the north-central U.S. Several Midwestern cities, including Minneapolis and Chicago, could face multiple days in the 90s. The East will also see a return of heat and humidity, though it's expected to be less severe than earlier in July.

Extreme heat warnings have been issued by the National Weather Service for regions including much of Utah, Wyoming, eastern Montana, and central/western North Dakota. These warnings signify expected extremely dangerous heat conditions, significantly increasing the risk of heat-related illnesses.

Meanwhile, the North American monsoon is expected to bring widespread thunderstorms to parts of the interior West. These storms could alleviate dryness but also bring hazards such as gusty winds, lightning, and potential wildfire ignitions. Flash flooding remains a concern, even from storms occurring miles away.