Another multiday, deadly severe weather outbreak spawned over 150 tornadoes in 22 states, along with damaging thunderstorm winds and hail from the Plains to the Midwest, South and East, including the most active day for severe weather so far in 2025. A total of 156 tornadoes were either sighted by spotters or confirmed by the National Weather Service in this outbreak from May 15 through the morning of May 21. Of those, 39 were categorized as "strong" tornadoes, those that produced at least EF2 damage on theEnhanced Fujita scalefrom which tornadoes are rated and peak winds are estimated. That total tornado tally is likely to change slightly in the coming days, as damage surveys by National Weather Service meteorologists are still being conducted. In addition to the tornadoes, there were over 2,000 reports of large hail and either damaging or strong thunderstorm wind gusts during the outbreak. Over 700 of those reports were from Friday, May 16, into early morning on Saturday, May 17, alone. Two of these tornadoes were rated EF4, a threshold the NWS classifies as violent tornadoes. Twisters this strong aren't rare, but they make up asmall fraction of America's yearly tornado tally. From zero to six EF4 tornadoes occurred in the U.S. annually from 2015 through 2024. The first violent tornado tracked through southern Illinois' Williamson County on the evening of May 16. Along its almost 17-mile path, one two-story home south of Marion was swept clean off its foundation, with just stubs of trees left behind the home by winds estimated up to 190 mph. Luckily, the residents of the home weren't there at the time. This was the strongest tornado to impact the region served by the National Weather Service's Paducah, Kentucky, office since the Dec. 10, 2021, outbreak. The other violent tornado tore a 60-mile path across Russell, Pulaski and Laurel counties, Kentucky, in almost 90 minutes late on the night of May 16. Heavy damage was reported in parts of the cities ofLondonand Somerset, with homes "wiped clean from their foundations" in London's Sunshine Hills subdivision, where 17 people were killed, according to the NWS damage survey. Peak winds were estimated at 170 mph. Two others were killed by the tornado in Russell and Pulaski Counties. That made this tornado the deadliest in the area served by the NWS-Jackson, Kentucky, office. There were three other deadly tornadoes on May 16. First, an afternoon EF3 tornado tore through the north side of the St. Louis metro area, killing five and injuring 38.Over 5,000 buildings were damaged in the city. The tornado crossed the Mississippi River and tracked through Granite City and Pontoon Beach, Illinois, before ending its almost 23-mile journey in the Southern Illinois University-Edwardsville campus. It was the strongest tornado in St. Louis since the April 22, 2011, EF4 that hit Bridgeton and Lambert International Airport. Other deadly tornadoes included an EF3 just north of Sikeston, Missouri (two killed), and an EF2 in Greene County, Indiana (one killed), both on May 16. Notable long-track tornadoes included a 35-mile path carved by an EF2 tornado south of Bloomington, Indiana, on May 16 and a 32-mile path in south-central Kansas on May 18. May 15 Among over 30 tornadoes, 15 of those were in Wisconsin, including four rated EF2. Two of those occurred in Dodge County, striking the towns of Juneau and Mayville. Eleven other tornadoes – all rated EF0 or EF1 – touched down in Lower Michigan. May 16 As mentioned earlier, this was the most active 24-hour period for severe weather during this extended siege, including anEF1 tornadothat started in Baltimore's Inner Harbor, then crossed interstates 95 and 895, damaging several warehouses before ending in the Dundalk Historic District. More bizarre that afternoon was a cloud of dirt and dust whipped up by outflow winds from thunderstorms over central Illinois and pushed northeastward into Chicagoland, northwest Indiana and even parts of Lower Michigan. This reduced visibility to zero in some outlying areas of Illinois, forcing some roads to close. According to the National Weather Service, it was believed to be thefirst dust storm to affect Chicago since May 31, 1985, which was also the day of a prolific tornado outbreak in Pennsylvania, Ohio and Ontario, Canada. The NWS also said it was the strongest Chicago dust storm since the Dust Bowl (May 10, 1934). May 18 NWS-Boulder noted two of the landspout tornadoes east and southeast of Denver were unusually strong, both rated EF2 in northeast Elbert County and northeast of Bennett in far eastern Adams County. Thewest side of Grinnell, Kansas, was struck by a slow-moving EF3 tornado that tracked only about 8 miles in 30 minutes. Greensburg, Kansas,leveled by an EF5 tornado in May 2007, was fortunate thatthree EF3 tornadoes on May 18 all remained either south or east of the town. A family of tornadoes spun up from a supercell in far northwest Oklahoma near Arnett. One of those produced at least EF2 damage, and hail up to the size of grapefruits was also reported. May 19-21 Among the roughly 60 tornadoes from May 19 into the early morning of May 21, several of these stood out. An EF1 tornado on May 19 in Dodge County, Nebraska,downed a tree on a home and sliced it in two, narrowly missing a man. And on May 20,a rare tornado emergency– the highest level of tornado warning from the National Weather Service – was issued before an EF2 tornado slammed into Madison, Alabama, near Huntsville.Another EF2 tornado in eastern Madison Countywas one of at least seven north Alabama twisters on May 20. Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. Extreme and bizarre weather are his favorite topics. Reach out to him onBluesky,X (formerly Twitter)andFacebook.