Dangerous heat bursts have been spiking temperatures across the US as people sleep. So what are they?
An intense burst of heat hit southwestern Oklahoma on Sunday, sending temperatures spiking into the high 90s.
In the city of Chickasha, which is located approximately 40 minutes from Oklahoma City, the weather event occurred in the early morning hours.
'Several hit southwest Oklahoma this morning. An intense burst of extreme heat hit Chickasha, Oklahoma at 5:15 a.m. Sunday morning, bringing the temperature to 95.6 degrees!' meteorologist and atmospheric scientist Matthew Cappucci wrote on the social media platform X.
But, what are heat bursts and how do they form? Here's what you should know.
What are heat bursts?
Heat bursts are localized and sudden increases of temperature that are associated with a thunderstorm.
The relatively rare atmospheric nighttime events are often accompanied by 'extreme drying,' according to the American Meteorological Society Glossary of Meteorology.
They're also characterized by gusty winds.
'Chickasaw went from 77 degrees and 80 percent relative humidity to 95.6 degrees and just 17 PERCENT humidity!' Cappucci noted. 'Chickasaw also gusted to 59 mph! Medicine Park, Oklahoma warmed to 81.2 degrees and gusted to 69 mph. Altus got to 89 degrees shortly after 2 a.m.'
How do they form?
Heat bursts need a dissipating thunderstorm or shower and a hot and dry midlevel atmospheric environment to form, according to National Weather Service forecasters. The midlevel atmosphere is around 20,000 feet above the Earth's surface.
Thunderstorms develop when moist and unstable air is pushed upward, and rain then falls from the storm. When the storm loses that upward moving current of air, it is dominated by a downward moving current of air.
Along with the combination of a hot and dry midlevel atmospheric environment, the downward current's moisture evaporates and cools the midlevel atmospheric layer, increasing its rate of descent toward the ground. The descending air will stop cooling when all the moisture has evaporated, warming the midlevel layer.
The heat burst occurs when the warm and dry air descends to the surface.
'As air sinks, it warms up (and dries out). And if you have an air pocket coming from high enough, it warms up a LOT by the time it reaches the surface. It also brings strong dry winds – like a desert hurricane,' Cappucci noted.
When and where do they happen?
Heat bursts typically occur in the spring and summer, when thunderstorm activity is associated with daytime heating.
While thunderstorms dissipate during the evening as they lose their main source of energy, heat bursts occur in the evening or overnight hours.
They can occur in many regions, but are most common in the Midwest and Plains states. However, they have previously occurred outside of that range. A significant weather event in 2012 brought one to Georgetown County, South Carolina. They've also struck the Southwest.
What are the associated dangers?
Climate change is making heat events more frequent and severe.
The rapid increase in surface temperatures - sometimes occurring in less than an hour and leading to a triple-digit high - can take residents by surprise. So can the associated winds, have been known to exceed 70 or 80 mph. They can rip the roofs off buildings and damage trees.
In Chickasha, they knocked out the power for more than 2,000 residents in Grady and Caddo counties, according KOCO 5.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
The Independent
5 hours ago
- The Independent
Cooler weather forecast after UK sees hottest day of the year
Sunday is expected to see 'cooler' and 'fresher' weather after the UK recorded the hottest day of the year, with a provisional high of more than 33C measured in Surrey. On Saturday, provisional temperatures recorded included 33.2C in Charlwood, Surrey, 26.9C in Bute Park in Cardiff and 27.2C in Aviemore in the Highlands. However, Sunday is expected to be a day of 'sunny spells and showers' with highs of around 27C and 28C, Met Office weather forecaster Dan Stroud said. Conditions are expected to feel 'a lot fresher' in the west of the country whilst remaining 'very warm and humid' in the east, he added. 'For the vast majority of the country, the temperature is going to be much, much closer to the mid, late June average. 'As we move our way through Sunday night into Monday, it's going to feel a lot fresher for us all, a lot more comfortable sleeping conditions.' This comes after a yellow warning for thunderstorms, covering parts of south-east Scotland, Yorkshire, the Midlands and Wales was issued by the Met Office from 5pm on Saturday until 3am on Sunday. Up to 40mm of rain could fall in less than two hours, the forecaster said, as it urged those in the warning areas, which includes Manchester, Derbyshire and Newcastle upon Tyne, to consider whether their location is at risk of flash flooding and to prepare accordingly. Overnight on Saturday, 'a lot cooler' and 'a lot fresher' conditions are forecast, with the exception of the east of England, including London and the South East, which could experience a 'tropical night', Mr Stroud said. 'In one or two spots that could potentially be a tropical night, which is where the overnight minimums actually fail to drop below 20 degrees,' he added. 'We haven't had any of those yet.' On Friday night, Somerset came 'very close' to recording a tropical night as temperatures dropped to a minimum of 19.7C, the forecaster said. An official heatwave is recorded when areas reach a certain temperature for three consecutive days, with thresholds varying from 25C to 28C in different parts of the UK. 'Many places' in England and 'one or two areas' in Wales, including Cardiff, entered a heatwave following Friday's highest temperatures, the Met Office previously said. An amber heat-health alert, issued by the UK Health Security Agency (UKHSA) for the first time since September 2023, for all regions in England remains in place over the weekend. The agency has warned that significant impacts are likely across health and social care services, including an increase in demand, during the alert period. Temperatures reached 32.2C in Kew, west London, on Thursday while Friday saw highs of 30.8C recorded in both England and Wales. Ireland's hottest temperature for almost three years of 29.6C was recorded on Friday in Mount Dillon, Co Roscommon, Irish forecaster Met Eireann said. Pharmacies have advised their patients to store medicines safely as the heat-health alert continues, adding that most medicines kept at room temperature should be stored in a cool, dry place, away from direct sunlight and hot areas, the National Pharmacy Association (NPA) said. Warmer temperatures may lead to some medicine losing its effectiveness or unwanted side effects, the NPC added. The hot weather comes as thousands of people watched the sunrise over Stonehenge in Wiltshire to celebrate the summer solstice on Saturday, marking the year's longest day.
The Guardian
6 hours ago
- The Guardian
Three people killed in North Dakota after tornado hits upper midwest
Powerful winds – including a tornado – that swept across parts of the upper midwest left three people dead and a regional airport heavily damaged, while nearly 150 million Americans were under a heat advisory or warning as the weekend warmed up in much of the US. A complex storm system wreaked havoc in parts of North Dakota, northern Minnesota and northern Wisconsin, with reported tornadic activity, large hail and strong wind gusts, according to Brian Hurley, meteorologist with the National Weather Service's Weather Prediction Center. Cass county sheriff Jesse Jahner said at a news conference Saturday that two men and a woman were killed late Friday at two locations around the town of Enderlin, North Dakota, about 40 miles (60km) south-west of Fargo. Thousands of households lost power. Hours earlier the National Weather Service in Grand Forks confirmed on social media that two deaths were attributed to a tornado that hit a home. Timothy Lynch, lead forecaster with the NWS office in Grand Forks, said the storm was confirmed as a tornado but crews were still working to determine its strength and highest wind speeds. He said the storm impacted the neighboring counties of Cass and Ransom. 'We still have people out investigating and gathering information on what happened. It was a pretty major event,' Lynch told the Associated Press. Governor Kelly Armstrong said in a statement that the NWS confirmed a second tornado touched down near Spiritwood, which is about 80 miles (130km) west of Fargo. Armstrong issued a statewide disaster declaration to respond to the damage. Heavy winds also swept across localized areas of Minnesota, and the NWS reported wind gusts of up to 106mph (171km/h) at Bemidji regional airport overnight. 'I cannot ever recall hearing a rushing wind like that!' Bemidji mayor Jorge Prince posted on Facebook in the early hours of Saturday. 'Emerged from our basement to find our neighborhood with lots of trees down and several homes with severe damage.' Prince also said officials were responding to many knocked down power lines and several gas line leaks. Localized torrential rain flooded the city's downtown and stalled vehicles, Beltrami county emergency management director Christopher Muller said. Many Bemidji-area businesses posted on social media to say they were without power and closed for the day. Muller warned people to prepare for 'long-term power outages' because of damage to infrastructure. Hurley said that same storm moved on in a weakened state to parts of Michigan. It was expected to cross over lower Ontario and back into the United States to hit upstate New York on Saturday night into Sunday. 'Still wind and hail threat,' Hurley said of the enhanced risk to upstate New York. 'It doesn't look like it's going to be as robust perhaps as we saw last night.' Warm and dry conditions coupled with frequent thunderstorms and lightning have resulted in more than 100 fires in the state since Wednesday. 'A lot of those fires are in vast wilderness areas of Alaska where fire is allowed to take its natural course,' said Sam Harrel, an information officer with the state's Division of Forestry and Fire Protection. But some fires were threatening populated areas, prompting evacuations in the interior region. Among them was a go order issued Friday for areas near Fairbanks, according to Harrel. A fire burning about 30 miles (50km) north of the entrance to Denali national park and preserve also prompted an evacuation 'due to escalating fire conditions', the Denali Borough said via Facebook. 'Numerous structures are now imminently threatened so aircraft including Air Tankers and helicopters are supporting the fire with retardant and water drops,' the borough added. Harrel said the fire was not affecting the status of the park but the smoke could worsen air quality for visitors.
Daily Mail
10 hours ago
- Daily Mail
At least 3 killed as power lines downed and locals trapped in cars as extreme winds sweep through a rural town
At least three people died in rural North Dakota after tornadoes violently ripped through three states, tearing down power lines, trapping locals in cars, and leaving 150million Americans under a heat advisory. Sheriff's deputies were called to Enderlin, North Dakota, near Fargo, around midnight on Friday after two storm chasers said they found two deceased people. Shortly after, a local fire department would find a third death nearby. 'Deputies found extensive damage to the area and began conducting well-being checks on people with several partner agencies,' the Cas County Sheriff's Office said in a statement. Cass County Sheriff Jesse Jahner said on Saturday that two men and a woman were killed. A complex storm system wreaked havoc in parts of North Dakota, northern Minnesota and northern Wisconsin, with reported tornadic activity, large hail and strong wind gusts, Brian Hurley, a National Weather Service meteorologist, told AP. Heavy winds also swept across localized areas of Minnesota, with wind gusts of up to 106 mph at Bemidji Regional Airport overnight. 'I cannot ever recall hearing a rushing wind like that!' Bemidji Mayor Jorge Prince posted on Facebook in the early hours Saturday. 'Emerged from our basement to find our neighborhood with lots of trees down and several homes with severe damage.' Prince also said officials were responding to many knocked-down power lines and several gas line leaks. Beltrami County Emergency Management said the damage to the Bemidji area is 'extensive.' Around 21,000 customers in Minnesota were without power, 20,000 in North Dakota, and 10,000 in Wisconsin, as of Saturday afternoon, according to Hurley said that same storm is traversing across parts of Michigan but is weakened. It will cross over lower Ontario, Canada, and back into the United States to hit upstate New York on Saturday night into Sunday. 'Still wind and hail threat,' Hurley said of the enhanced risk to upstate New York. 'It doesn´t look like it´s going to be as robust perhaps as we saw last night. Almost 59million Americans are under an extreme heat warning Saturday, Hurley said, as the high temperatures combined with humidity push an above-average heat index for the Northern Plains and the Midwest. Parts of Nebraska, the Dakotas, Minnesota and Iowa could face temperatures 'easily 20 degrees above normal,' Hurley said, including some areas reaching the triple digits. It may be expected in July, he said, but it's rarer to see in June. 'A lot of these areas have been pretty cool with rain over the last month or so, so it´s going to be a little bit of a shock,' Hurley said. Cooling centers were open in cities including Omaha and Minneapolis as officials warned the public of dangerously hot conditions. An additional 84million people were under a heat advisory as forecasters expect the extreme weather to migrate eastward toward the Great Lakes, the Mid-Atlantic and the Northeast, where the 'heat risk category is a four of four' into early next week, Hurley said. Meanwhile, parts of the Great Basin and the Southwest may be hot but are seeing relief from below-normal temperatures.
