Storm Track Severe Weather Guide Severe weather can happen at any time across the Northland. Severe weather can pop up quickly in the summertime. Knowing the correct terminology the WDIO Storm Track meteorologists use during times of severe weather can help keep you and your family safe. It is important to always keep a close eye on the forecast when heading out to enjoy your day. Severe Thunderstorm Terminology Severe thunderstorms are storms capable of producing 1” in diameter or greater hail and could have winds at or greater than 58 miles per hour. Tornadoes are possible during severe thunderstorms. A Watch or Warning will be issued when needed.