About 100,000 thunderstorms occur yearly in the United States. Only 10 percent are severe, but all can produce lightning, strong winds, hail, tornadoes and heavy rain. Thunderstorms happen year-round, but most commonly on spring/summer afternoons and evenings.
Severe thunderstorm watches tell when and where severe thunderstorms are likely to occur.
Severe thunderstorm warnings go out when storms are reported by spotters or appear on radar.
Safety tips in a thunderstorm
- Stay aware. Watch for approaching storms. Check the weather forecast before heading outdoors. Postpone outdoor activities when thunderstorms are forecast. Tune in to a weather radio for 24/7 updates from the National Weather Service.
- Know what to do. Take safe shelter immediately inside a sturdy building, away from windows, doors and electrical appliances. (You want to avoid contact with conductors of electricity, appliances, metal objects and water.) Get out of boats and away from water. Find a low spot (but not one that will flood) away from trees, fences and poles. If you are in the woods, take shelter under shorter trees. If lightning strikes close by, make yourself the smallest possible target and minimize your contact with the ground. (Squat low on the balls of your feet. Put your hands on your knees. Place your head between your knees.)
- Other tips? Don’t shower or bathe. Turn off air conditioners, since power surges can overload them. Avoid landline telephones and unplug all unnecessary electrical appliances, telephone lines and metal pipes, which conduct electricity.