On June 18–19, 2021, a severe weather outbreak affected the Midwestern United States, affecting the states of Illinois, Indiana, and Ohio. Floods, caused by training convection,[3] caused $51.7 million in damage and causing rainfall amounts of up to 7 inches (180 mm) across western Indiana,[4] causing one death.[5] Hail damage also occurred from the storm complex system, which caused damage across several states that amounted to $1.9 million. A tornado outbreak also ensued, with 2 EF2 and 5 EF1 tornadoes confirmed, which caused $1.56 million in damage.
On the morning of June 18, heavy rainfall-producing convection developed across portions of Ohio in an unstable environment, which included an enhanced moisture axis.[6] Afternoon heat resulted in the development of severe thunderstorms.[7] However, the thunderstorms had not fully matured until later that evening, as warm air kept the thunderstorms from becoming severe.[7] Thereafter, severe thunderstorms originated from a boundary front after the weakening of the warm air, which led to repeated rounds of thunderstorms over portions of southern Illinois, Indiana, and Ohio, in which were situated by a complex of thunderstorms over Iowa.[7]
The hail event associated with the storm complex included a 4-inch hailstone, which fell in Bridgewater, Iowa, and hail up to 1.5 inches in diameter were reported in the Quad Cities area.[8][9] Large hail impacted northern fringes of Indianapolis, Indiana, with one event in which hail damaged parked cars near Castleton Square Mall.[10] The hail also caused damage across the Dayton metropolitan area in Ohio which damaged vehicles in Northridge.[11] The hail event alone caused $1.9 billion in damage.[12]
One person drowned in Bloomington, Indiana after he drove his car through floodwaters and was swept into a swollen Clear Creek.[13] One street in Bloomington was several feet underwater as other streets and cars were inundated, and as much as seven inches of rain was reported in Ellettsville, Indiana.[5][14][4] Beaches at Monroe Lake were closed after heavy rainfall rose water levels.[15]
The highest wind gusts were recorded around 80–90 miles per hour (130–140 km/h), in Knox and Fulton counties in Illinois.[16]
Seven tornadoes touched down in Kentucky, Indiana, Ohio, and Illinois as a result of the severe weather outbreak. Two EF2 tornadoes caused severe damage to trees, outbuildings, power poles, and homes near Portland, Indiana and Fort Recovery, Ohio respectively.[17][18] A high-end EF1 tornado struck the town of Milan, Indiana, downing numerous trees, destroying a garage, and tearing shingles, siding, and gutters from homes. Another EF1 tornado near Moores Hill, Indiana damaged two homes and downed trees. An EF1 tornado also caused roof and tree damage near Germantown, Ohio, while another EF1 tornado damaged farm buildings, crops, and trees near the town of DeLong, Illinois. Numerous reports of straight-line winds, large hail, and flooding were received as well.[19][20] More than 40,000 people lost power during the storm.[21] Numerous flash flood watches, warnings, and tornado warnings were issued in parts of Illinois, Indiana, and Ohio.[22] Combined, the tornadoes inflicted $1.56 million in damages.