>> reporter: a wild weekend weather across the country. tornado warning sirens in chicago >> tornado. >> reporter: sightings nearby with heavy rain drenching the city and flooding the streets in detroit, the rain shut down interstates trapping vehicles. meanwhile in the northwest a dome of heat is punishing cities like seattle and portland where the all-time 107-degree temperature record could be shattered this weekend the forecast there expected to break 110 degrees. across the region, at least 25 million people in 6 states are under heat alerts. >> we are closing for the heat wave. i don't want to risk the lives of my staff or other patrons who might be out here. >> reporter: others are doing what they can to survive the heat. >> we brought a lot more ice today. >> reporter: the olympic track & field trials in eugene, oregon, moving events earlier to beat the worst of the heat. >> this is a brutal way to make an olympic team >> reporter: in seattle where more than half of households don't have