Tornado outbreak kills over 20 people as severe storms target East Coast

• Heavy damage has been found in multiple communities, particularly near Dawson Springs, Ky., where a large tornado was on the ground for many miles as it traveled northeast, prompting four separate "tornado emergency" warnings, including for the communities of Earlington and Mortons Gap.
• The NWS' Paducah office said on X Monday preliminary findings indicated "high end EF-3 damage so far from the long track tornado" that impacted these areas.

Zoom in: The tornado lofted debris to at least 35,000 feet above the ground as it followed a similar path to the deadly Mayfield tornado in 2021, which killed 24 people, though the overall toll was higher across a broader region of the state.

• A large campground near Claremont, Kentucky, crowded with Memorial Day campers, was affected by these storms, prompting rescues. The town was also damaged.

Threat level: The thunderstorms that hit the region were caused by the same weather system that sparked the deadly tornadoes in the Plains on Saturday night.

• That system was causing widespread travel disruptions into Monday as it threatened the East Coast on Memorial Day, where NWS predicted a "slight risk" of severe weather into the night — including damaging winds, hail and a few tornadoes.
• This is a level 2 out of 5 on the risk scale.

State of play: The latest storm-related death occurred in Mountain Brook, Alabama, when a tree fell onto a home early Monday, per the local fire department.

• Most of the deaths reported over the holiday weekend occurred in Cooke County, Texas, where two young children were among at least seven people killed in a tornado.
• Texas Gov. Greg Abbott said at a Sunday briefing at least 100 people were injured in the storms and a disaster proclamation was in effect for 106 counties affected by severe weather.
• In Arkansas, where eight storm-related deaths were confirmed, Gov. Sarah Huckabee Sanders declared an emergency for affected communities.
• In Kentucky, five storm-related deaths have been confirmed, while Oklahoma officials confirmed two fatalities from the severe weather.
• Multiple injuries and structural damage were reported in Mountain View, Missouri, where preliminary NWS findings indicated an EF-3 tornado touched down.

Context: Sunday was the busiest severe weather day of this active season so far, according to reporting by the Storm Prediction Center.

• This year is now the second-busiest tornado season to date, behind only 2011, with 989 tornado reports through May 26. This data is preliminary, as multiple reports of the same tornado may have been recorded.

Between the lines: Climate change affects the conditions in which thunderstorms form and may be leading to larger outbreaks, though fewer of them, by adding to the instability of the atmosphere while simultaneously cutting back on wind shear.

• The repeat storms in the Plains, Mississippi River Valley and Ohio Valley are related in part to a powerful heat dome over Mexico, which is helping to supply warm air from the south.
• Climate scientists have published numerous studies attributing extreme heat events to climate change.
• All-time high-temperature records continue to be broken in Mexico and Central America, including Mexico City's all-time highest temperatures on record.

Zoom out: Extreme heat enveloped the Gulf Coastal states from Texas to South Florida this weekend as the heat dome meanders slightly to the north.

• The intense heat dome is influencing the position of the jet stream across the U.S., which helps provide the energy triggering severe weather outbreaks.

Go deeper: Buttigieg says climate change is affecting transportation

Editor's note: This a breaking news story. Please check back for updates.