Intense thunderstorms rumbled across southern Minnesota on Monday April 13, 2026, producing the state's first tornadoes of the year along with a swath of damaging hail.
A developing area of low pressure in eastern Nebraska produced a warm front in northern Iowa early on Monday, separating a sultry air mass to the south from much cooler conditions to the north. This warm front moved northward through the day, crossing the Minnesota/Iowa border in the late morning and making it as far north as Mankato and Red Wing by late afternoon.
With strong winds aloft, shifting wind directions across the warm front, and with access to abundant heat, moisture, and energy to the south, the environment was primed for very strong and long-lasting thunderstorms.
Thunderstorms developed right on the warm front, first near Faribault in Rice County just after 3 PM. That storm becoming severe and produced large hail by 325 PM, and for 2-3 hours it produced a swath of ping pong ball to tennis ball-sized hail as it trudged across Rice Goodhue, and Wabasha counties, making its way toward Lake City and Wabasha.
Other severe thunderstorms developed after 5 PM along the warm front, arcing westward and southwestward towards Sioux Falls, SD. These storms produced large hail in serial fashion, with reports of quarter, golfball, tennis ball-sized sized,and larger, reported from Luvurne in far southwestern Minnesota, to Windom, to St. Peter.
The large hail caused damage to cars, siding and rooftops across streaks of southwestern, southern, and southeastern Minnesota. A few of the southern-most storms also produced tornadoes, with one reported near Truman and Amboy, another reported near Matawan, and one reported near Elmore.
The first storm mushroomed quickly into a large "supercell," and most of the remaining storms also became supercells, which are are thunderstorms that have deep, persistent rotation of the main updraft, enabling them to acquire both longevity and high intensity. As is often the case, these supercell thunderstorms remained isolated from one another for several hours, generally tracking along the warm front itself, meaning that many areas were hit by strong or severe thunderstorms multiple times during the evening. The storms eventually grew "upscale" into a large well-connected complex, losing their supercellular charactersitics and transitioning away from large hail and tornado threats, to strong wind and heavy rainfall threats.
Posted April 15, 2026
KAB