A heat dome over the eastern half of the US is expected next week

Key Points:

• A heat dome will cause dangerously hot and humid conditions across the eastern half of the U.S. next week, bringing the region's most widespread heat wave of the summer so far, with heat index values reaching up to 115 degrees in some areas.
• Major cities including Chicago, Detroit, St. Louis, Dallas, and Nashville are expected to experience their highest temperatures of the year, with humid air spreading from the South into the Midwest and Northeast by midweek, creating hazardous heat conditions for millions.
• Tens of millions of people face major to extreme heat risk, with nighttime temperatures remaining high due to humidity, increasing the danger of heat-related illnesses such as heat exhaustion and heat stroke; heat is the deadliest weather hazard in the U.S.
• In the West, a large jet stream shift is causing a cooldown accompanied by powerful winds, intensifying critical fire weather conditions in Utah and neighboring states, including a rare "particularly dangerous situation" red flag warning for the Cottonwood Fire.
• The Cottonwood Fire in Utah remains uncontained and is considered likely the state's most destructive wildfire on record, with high winds expected to continue fueling ongoing fires and fire danger through the weekend.