
Why do heat domes bring oppressive temperatures?
Dangerously hot and humid conditions are choking nearly the entire eastern half of the United States this week, caused by a 'heat dome' that's parked over parts of the country.
Heat alerts were in effect Wednesday for around 150 million people. Temperatures over 95 degrees Fahrenheit were widespread across the Ohio Valley and through the East Coast. 'Extremely dangerous heat' is expected to persist through Thursday, according to the National Weather Service.
But what is a heat dome, and why does the phenomenon bring oppressive heat with it?
A heat dome occurs when a strong and persistent region of high pressure sits over land and traps hot air, like a lid on a pot.
Heat domes are usually affected by the behavior of the jet stream, a ribbon of fast-moving air high in the atmosphere that flows from west to east in the Northern Hemisphere and affects weather systems.
The jet stream is fueled by temperature differences between the colder polar region to the north and warmer air masses to the south. As the jet stream flows around the planet, it can ripple in places, creating troughs and ridges that often result in unusual weather patterns.
Certain ripples can, for instance, amplify cold snaps. Others can move hot air over land, blasting heat and intensifying humidity.
Heat domes can linger for days or weeks, fueling prolonged heat waves that can turn deadly. Heat-related illness and death can affect any person of any age, but children, people with pre-existing health conditions and the elderly are particularly susceptible when temperatures spike.
Climate change is also increasing the frequency, intensity and duration of heat waves around the world, studies have shown. The planet's 10 hottest years since 1850 have all occurred in the past decade, according to the National Oceanic and Atmospheric Administration.

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles


Reuters
5 hours ago
- Reuters
Balkans braced for record-breaking heatwave
BELGRADE, June 26 (Reuters) - People braving an early summer heatwave sought relief in lakes and mountains across the Balkans this week, as health authorities urged residents to stay in the shade and drink plenty of fluids to avoid dehydration. Meteorologists in Serbia said on Thursday that yesterday was the hottest day in the Balkan country since measurements began in the 19th century, forecasting even higher temperatures in the coming days. Serbian authorities advised people to stay in shaded or air-conditioned areas, avoid direct exposure to the sun from 11 a.m. to 5 p.m., and warned that a prolonged drought could threaten harvests. Meteorologists forecast temperatures reaching 40 degrees Celsius (104 degrees Fahrenheit) across the Balkans in the coming week. In Montenegro, throngs of tourists left the sweltering Adriatic coast in the south for the cooler Durmitor mountain resort in the north, where temperatures at about 1,500 metres above sea level were significantly lower than on the beaches. "We planned to explore the coast, but we decided to head north because it was so hot," said Eric, a tourist from the Netherlands. In Croatia, which has battled wildfires along its Adriatic coast in recent days, people sought respite from the heat at Bundek Lake, just outside the capital Zagreb. At Lake Ohrid in southern North Macedonia, people cooled off in the water, although some were unfazed by the conditions. "We're used to heat in Australia," said Blagoja Lozanivski, a North Macedonian native now living in Australia.


Reuters
5 hours ago
- Reuters
Scorching Club World Cup raises concerns for 2026
NEW YORK, June 26 (Reuters) - Soaring temperatures at this year's Club World Cup have raised concerns over afternoon kickoff times at the 2026 World Cup, as the expanded tournament poses logistical challenges for organisers. A heatwave across the United States saw Borussia Dortmund players face South Korea's Ulsan in Cincinnati on Wednesday, with temperatures exceeding 90 degrees Fahrenheit (32.2°C) with the kickoff at 3 p.m. local time. Players took advantage of FIFA's once-per-half cooling breaks at games this week while Chelsea manager Enzo Maresca told reporters it was "impossible" to organise regular training sessions in the afternoons in sweltering Philadelphia. Global players' union FIFPRO said the conditions should "serve as a wake-up call". "As climate change is making extreme weather conditions, including dangerous heat, an increasingly urgent issue for everyone in the football industry, the risk posed by kickoffs in very high temperatures is real and growing," a FIFPRO spokesperson told Reuters. FIFPRO urged global soccer bodies to re-evaluate kickoff times to better address heat conditions, while praising organisers like FIFA for their flexibility in adding cooling breaks to games. "We believe there is still a lot more that should be done to prioritise player health and safety," said FIFPRO. "Current protocols and laws of the game require urgent revision - this is a challenge the entire football industry must take on together." FIFA did not immediately respond to a request for comment. Match times for the 2026 World Cup, co-hosted by the United States, Mexico, and Canada, have yet to be announced, but organisers may face challenges if sweltering conditions return. Heat issues would come as no surprise to those who were at the tournament in 1994, the last time the United States played host. "The cacophony of complaints echoing across the land could drown out the cheers at the nine stadiums where they are showcasing international soccer's quadrennial event," the Los Angeles Times wrote a week into that tournament, as high temperatures had fans steaming. More than 90,000 fans piled in to watch the final in Pasadena, where temperatures reached 100 degrees Fahrenheit (37.8°C). It was the last time that a World Cup final was played entirely in daylight. With the tournament expanding from 32 to 48 teams, afternoon kickoffs may be unavoidable to meet scheduling demands and accommodate lucrative European broadcast markets. "The big broadcasters are investing a ton of money, so they're not super interested in having the schedule changed to accommodate heat if it means that they're not going to make as much ad revenue," said Madeleine Orr, an author and sports ecologist. Host cities at the highest heat risk in 2026 - including Miami, Monterrey, Philadelphia, Kansas City, Boston and New York - should avoid kickoff times in the hottest afternoon hours, Orr said in a study she co-authored earlier this year. Orr said pushing more afternoon games to one of the tournament's four indoor venues in Atlanta, Dallas, Houston and Vancouver could be part of the solution. "You need your broadcasters to be happy," said Orr. "If we're talking about safety first, it's not complicated at all. If we're talking about hosting a major event and making it financially feasible and seeing this event happen at all, it's complicated."


NBC News
6 hours ago
- NBC News
Why do heat domes bring oppressive temperatures?
Dangerously hot and humid conditions are choking nearly the entire eastern half of the United States this week, caused by a 'heat dome' that's parked over parts of the country. Heat alerts were in effect Wednesday for around 150 million people. Temperatures over 95 degrees Fahrenheit were widespread across the Ohio Valley and through the East Coast. 'Extremely dangerous heat' is expected to persist through Thursday, according to the National Weather Service. But what is a heat dome, and why does the phenomenon bring oppressive heat with it? A heat dome occurs when a strong and persistent region of high pressure sits over land and traps hot air, like a lid on a pot. Heat domes are usually affected by the behavior of the jet stream, a ribbon of fast-moving air high in the atmosphere that flows from west to east in the Northern Hemisphere and affects weather systems. The jet stream is fueled by temperature differences between the colder polar region to the north and warmer air masses to the south. As the jet stream flows around the planet, it can ripple in places, creating troughs and ridges that often result in unusual weather patterns. Certain ripples can, for instance, amplify cold snaps. Others can move hot air over land, blasting heat and intensifying humidity. Heat domes can linger for days or weeks, fueling prolonged heat waves that can turn deadly. Heat-related illness and death can affect any person of any age, but children, people with pre-existing health conditions and the elderly are particularly susceptible when temperatures spike. Climate change is also increasing the frequency, intensity and duration of heat waves around the world, studies have shown. The planet's 10 hottest years since 1850 have all occurred in the past decade, according to the National Oceanic and Atmospheric Administration.