Weather forecasters 'increasingly concerned' about violent storms in South
The environment is "forecast to be one of the more unstable we have seen during the summertime," said Keith Stellman, a meteorologist with the weather service in Peachtree City/Atlanta.
As a deadly heat wave continued to scorch much of the eastern half of the country, a round of thunderstorms known as a "ring of fire" was cropping up along some of the edges of the heat dome, forecasters said on June 25.
The Southeast could feel the strongest brunt of storms in the afternoon and evening. National Weather Service forecasters say they're growing "increasingly concerned" about the risk of violent weather with high winds and hail through Georgia and the Carolinas.
The environment is "forecast to be one of the more unstable we have seen during the summertime," said Keith Stellman, a meteorologist with the weather service in Peachtree City/Atlanta. Their weather models indicate the possibility of greater than 70 mph winds in some of the storms, particularly along and to the east of I-85, he said.
A ring of fire is a pattern of thunderstorms that tend to form along the edges of a heat dome. Tens of millions of Americans were under heat warnings and advisories from the National Weather Service the morning of June 25 in over a dozen states from the Midwest to much of the East Coast. The heat has so far led to at least one reported death in Missouri.
The weather service is urging people to be cautious and aware of these summer thunderstorms when they are outdoors. More than 30 people have been injured by lightning across the U.S. over the past week, often caught by lightning flashing from burgeoning thunderstorms.
"That's one thing about summer thunderstorms," they can form and intensify quickly, said Bob Oravec, lead forecaster with the weather service in College Park Maryland.
A risk of severe thunderstorms also could bring damaging wind gusts and hail along other sections of the heat dome's perimeter, including other parts of the Southeast and mid-Mississippi Valley, according to the Storm Prediction Center.
What is a ring of fire?
A ring of fire occurs when thunderstorms and rain form along the border of a ridge of high pressure, according to the weather service. When the ridge stays in place, it traps heat over an area, causing a heat dome. In the heat dome, the weather will remain relatively stable, according to the weather service. That's because clouds have difficulty forming, so thunderstorms are kept away, AccuWeather reported.
Along the edges of the heat dome, however, storms can pop up in clusters. The air there is cooler up in the atmosphere, allowing storm-producing clouds to form, according to AccuWeather.
Storms can form anywhere in the clockwise air flow around the dome, Oravec said. So far in the recent heat dome, storm activity has been stronger to the west where lift in the atmosphere and moisture have been stronger, he said, but the forecast for the afternoon of June 25 shows stronger activity over the southeast.
Where will thunderstorms form?
Thunderstorms packing dangerous wind gusts are expected across parts of North and South Carolina and the Southeast on June 25, according to the Storm Prediction Center. Along a corridor from Nebraska into Iowa, southern Wisconsin and northern Illinois, damaging wind gusts and hail are also expected to form.
About 26 million people live in areas with a slight risk for severe storms, with major cities at risk, including Charlotte, Raleigh, Greensboro and Durham, North Carolina, and Atlanta. A slight risk for severe thunderstorms in parts of central Nebraska through northern Iowa and southern Minnesota will increase on June 26, forecasters said. AccuWeather also reported a threat of severe thunderstorms extending through Pennsylvania, the southern tier of New York to New Jersey, and southern New England.
Over the next few days, the weather service said scattered thunderstorms are expected from the Southwest through the Upper Great Lakes region. Storms in New Mexico and west Texas could also lead to flash flooding, particularly over a burn scar in Ruidoso, New Mexico, the weather service said.
Extreme heat turns deadly
The heat wave will continue to impact over 150 million people across a large swath of the eastern half of the country on June 25, the weather service said.
The heat warnings and advisories blanket states from the Lower Mississippi Valley and Midwest to much of the East Coast. The Ohio Valley is experiencing the longest stretch of heat, with record high temperatures expected to continue through June 27, the weather service said.
Records were broken in several areas for high temperatures on June 24, with New York City seeing its hottest day since 2012, the weather service said. Across the region of the heat wave, high temperatures on June 25 are expected to reach the upper 90s and nearing 100 degrees during the day, while struggling to drop below 80 overnight in some East Coast urban areas.
A woman in St. Ann, Missouri, died in her home due to the dangerous heat after having no water or air conditioning for at least three days, KDSK-TV reported. Extreme heat caused disruptions to travel, tourist attractions and even a graduation ceremony earlier in the week.
Contributing: Doyle Rice, Christopher Cann and Thao Nguyen, Paste BN
(This story has been updated to add new information.)