The National Weather Service released yesterday a storm warning for most of the Milwaukee state, as a powerful storm system with hailstorms and tornadoes approached from Minnesota. As the storm weakened, the authorities began investigating the damages and the full reports are soon to be released.

According to the weather agency, St. Croix County reported severe hailstorms, while Barron and Polk counties faced winds of 60 mph and also golf ball-sized hail.

The series of thunderstorms left a tragic trail behind, killing seven people and injuring dozens in Iowa. Also, a 2-year-old was killed during a different storm in St. Paul, Minnesota. About four dozen homes were damaged and at least 20 people were unaccounted for.

Last night, another tornado watch was issued by the National Weather Service, after noticing the atmospheric conditions which were favorable for the formation of such a weather phenomenon, mentioning parts of northern Illinois and southern Wisconsin, which included the Winnebago, Boone, Stephenson and the Ogle counties.

Most tornadoes present wind speeds between 40 mph and 110 mph, are about 250 feet high and travel for a few miles before dissipating.

According to the weather observers, the worst has passed and the storms are expected to weaken starting today but several showers and mild thunderstorms will still be present.