Eastern U.S. bracing for a sprawling heat dome next week

Forecasters expect a heat dome to lock over the eastern half of the United States next week, driving heat indices to 100–110°F (with some spots up to 115°F) and producing oppressive humidity with little overnight relief. Major cities including Chicago, Detroit, St. Louis, Dallas and Nashville could see their hottest days of the year as millions face Level 3–4 extreme heat risk while the jet stream shifts and traps hot air; the West cools somewhat in contrast. Utah faces extreme fire weather with rare “particularly dangerous” red-flag warnings and gusts up to 50 mph as ongoing fires burn nearby. The heat is projected to spread into the Northeast by midweek, and a potential westward shift toward the Plains could arrive around the Fourth of July weekend.