A strong storm system last weekend produced deadly tornadoes that killed seven people in central Iowa.

Dennis Todey, head of the Midwest Climate Hub in Ames Iowa, says the strength of the storms was surprising….

Todey says they aren’t sure what the outbreak may mean for the rest of the severe season….

Todey says the tornadoes were produced by a clash of warm and cold air masses….

Much of the region also saw a massive outbreak of tornadoes in the middle of December.