A heat dome will bring dangerously hot and humid conditions to the eastern half of the United States next week in the region’s most widespread heat wave of the summer so far.
The heat domes will be built in response to major changes in the jet stream that are causing major cooldowns in the Western world. In Utah and neighboring states where large and destructive fires continue, the cooling down will bring strong winds that will worsen already dangerous fire weather conditions.
Temperatures in major cities such as Chicago, Detroit, St. Louis, Dallas and Nashville could reach their highest levels of the year by early next week. Conditions will become even more severe with a large flow of moist air extending from the South to the Midwest. The muggy weather pattern will then expand from east to northeast by midweek.
Thermal domes stagnate and trap hot air for days, causing the heat index, or the perceived temperature that takes humidity into account, to rise to dangerous levels over large areas. Millions of people will see so-called “feel-like” temperatures reach 100 to 110 degrees. Temperatures can reach up to 115 degrees in some places.
Heat waves are becoming more intense and frequent around the world due to anthropogenic global warming caused by fossil fuel pollution. Two recent examples are the record heatwave in Europe last week and the record heatwave in the western United States in March.
Although this upcoming heatwave will not rival record-breaking extreme weather in most regions, it remains dangerous as scorching conditions will continue for several days.
The heat and humidity are expected to intensify across the South this weekend and move north toward the Midwest and Great Lakes by early next week. Parts of the Northeast, including New York City, Pittsburgh, Pennsylvania, and Washington, D.C., will feel increasingly hot and humid by Tuesday or Wednesday.
Large areas of the South will experience high temperatures in the low 90s to near 100 degrees, while high temperatures in the low to mid-90s will be common in the Midwest, mid-Atlantic coast and parts of the Northeast. The World Cup game, to be played at New York/New Jersey Stadium on Tuesday at 5pm ET, could start a little hot with temperatures in the upper 80s and heat index in the low 90s.
For one or more days next week, tens of millions of people from the Deep South as far north as parts of Minnesota, Wisconsin and Michigan, and as far east as New York and the Mid-Atlantic will be at a Level 3/4 “severe” or Level 4/4 “Extreme” heat risk for one or more days next week, the National Weather Service said.
The Bureau of Meteorology says such extreme heat can affect anyone without proper cooling and hydration. There is expected to be little relief overnight, as the high humidity will prevent temperatures from dropping much.
Low temperatures next week will not dip below the low to mid 70s in the Midwest and Great Lakes. It can be difficult to get much below 80 degrees in urban areas.
According to the Centers for Disease Control and Prevention, prolonged exposure to extreme heat can lead to illnesses such as heat exhaustion, heat cramps, and the most serious type of heat stroke. According to the National Weather Service, emergency room visits due to heat stroke spike on “severe” and “very dangerous” days.
Heat is also the deadliest weather in the United States, causing more deaths on average each year than tornadoes, hurricanes and lightning combined, according to National Weather Service statistics.
It’s still unclear exactly how long the heat dome will last next week, but it could start moving west toward the Plains by the Fourth of July weekend. While the South will continue to experience hot, sticky weather, the Midwest, Great Lakes and Northeast could see some relief during or shortly after the holiday season.
This first widespread heatwave comes just as the central and eastern United States begins its hottest period of the year.
According to the National Center for Environmental Information, most of these regions experience their hottest days on average in July, while the Southern Plains and Lower Mississippi River Valley typically experience peak heat in August.
On Friday, a Level 3/3 Very Severe Fire Weather Condition was issued for fire-prone areas of Utah, northern Arizona and eastern Nevada.
The threat is so serious that the National Weather Service office in Salt Lake City has issued the first-ever “Particularly Hazardous Conditions” red flag. This includes south-central Utah and the Cottonwood Fire, currently the state’s largest inferno. This extremely rare designation is reserved for the most extreme fire weather conditions.
“This is a particularly dangerous situation that poses a significant threat to life and property in the event of a wildfire outbreak or an existing fire,” the warning states. “In some cases, if a fire approaches, safe and timely evacuation may not be possible.”
Wind gusts of up to 80 mph can cause both active and newly started fires.
Several large wildfires continue to burn in south-central Utah. The Cottonwood Fire east of Beaver, Utah, has burned through an area roughly the size of Salt Lake City in just a few days, and remains 0% contained. Although evacuation measures have been put in place for the fire, state and local officials believe it is likely Utah’s most destructive and costliest wildfire in history.
The total number of structures destroyed by the fire is unknown as damage assessments are planned or underway. The deadliest fire in Utah history was the Dollar Ridge Fire in 2018, which destroyed 74 homes, said Carl Hunt, public information officer for the Utah Department of Forestry, Fire and Lands.
Further north, the Iron Fire near Eureka, Utah, has burned more than 40,000 acres after forcing mandatory evacuations earlier this week.
Fire danger will remain high in many of the same areas on Saturday as strong winds and low humidity continue.
