A thunderstorm is considered severe if it produces hail at least 2.5 cm in diameter or has wind gusts of at least 93kph km/h. Every thunderstorm produces lightning, which kills more people each year than tornadoes or hurricanes. Heavy rain from thunderstorms can cause flash flooding, and high winds can damage homes and blow down trees and utility poles, causing widespread power outages.
Know the Difference
- Severe Thunderstorm Watch – Severe thunderstorms are possible in and near the watch area. Stay informed and be ready to act if a severe thunderstorm warning is issued.
- Severe Thunderstorm Warning – Severe weather has been reported by spotters or indicated by radar. Warnings indicate imminent danger to life and property.
- Listen to local news or this safety service to stay informed about thunderstorm watches and warnings. Watch for signs of a storm, like darkening skies, lightning flashes or increasing wind.
- If a severe thunderstorm warning is issued, take shelter in a substantial building or in a vehicle with the windows closed. Get out of mobile homes that can blow over in high winds
- If you are outside and cannot reach a safe building, avoid high ground; water; tall, isolated trees; and metal objects such as fences or bleachers.