More than 35 million Americans from Wisconsin to Oklahoma were at risk from a severe weather outbreak on Friday that included violent storms, including tornadoes, that tore through multiple states.
As of early Friday evening, there were 12 reported tornadoes across five states and a confirmed tornado on the ground in Illinois on Friday.
In Stephenson County in northwestern Illinois, authorities said a powerful storm, believed to be a tornado, tore through the village of Lena on Friday afternoon, causing significant and widespread damage.
In this screen grab from a video, a possible tornado is shown in Rochester, Minn., on April 17, 2026.
Greg Anderson
The Stephenson County Sheriff’s Office said there were no reported deaths or serious injuries but the storm left extensive damage to homes and businesses and scattered debris and downed power lines in its wake.
The sheriff is due to hold a press conference Saturday morning to provide an update on the storm response.
A tornado warning in the Milwaukee area later Friday evening led to the evacuation of the Air Traffic Control tower at the Milwaukee Mitchell International Airport.
The greatest risk for strong tornadoes was in central and southern Wisconsin through eastern Iowa. The northern halves of Illinois and Missouri have the greatest risk for destructive winds.
In this screen grab from a video, a possible tornado is shown south of Oslo, Minn., on April 17, 2026.
@MuskyWeatherGuy/X
Tornado watches were in effect for parts of Kansas, Oklahoma and Missouri — including Kansas City, St. Louis and Chicago — through 11 p.m. CT. Some intense tornadoes, significant wind gusts to 75 mph and scattered large hail were all possible.
People help clean up downed trees that were toppled during severe overnight storms, April 14, 2026, in Deforest, Wis.
Jon Elswick/AP
As storms develop Friday afternoon, there is a chance for discrete supercells with very large hail, strong tornadoes and destructive, straight-line winds.
The National Weather Service on Friday upgraded the severe weather potential for parts of the Heartland. The agency’s Storm Prediction Center added a level 4 of 5 “moderate risk” for parts of northwest Oklahoma, central and eastern Kansas and west-central Missouri. This includes Kansas City, Missouri, and Wichita and Topeka, Kansas.
Thunderstorms were also expected to fire up later Friday afternoon into the evening with the potential to produce damaging hail greater than baseball-size, very strong and destructive wind gusts of up to 90 mph and some tornadoes.
Severe Weather Outlook Map
ABC News
Flash flooding is also possible, with flood watches issued from Missouri to northern Michigan.
The severe weather outbreak came after flooding and tornadoes already impacted parts of the region this week.
The NWS confirmed at least 28 tornadoes across nine states stretching from California to New York this week, with Wisconsin, Iowa and Illinois hardest-hit.
The storms are bringing additional rain to parts of Wisconsin and Michigan, which saw widespread flooding, prompting states of emergency. The states could see an additional 1 to 3 inches of rain on top of their extremely saturated soil, expanding river flooding and the risk of sinkholes.
A 41-year-old man was killed by a lightning strike Wednesday evening in a parking lot in Waukesha County, Wisconsin, authorities said.