A severe thunderstorm is associated with wind speeds of 58 miles per hour or more, hail 0.75 inch in diameter or larger and heavy rain. This information will be available via a National Oceanic and Atmospheric Administration (NOAA) Weather Radio alert, radio, and television broadcasters
Note: Winds of 75 miles per hour or more is considered hurricane strength.
Treat this like a tornado warning. Use the same shelter you would for a tornado.
According to the National Center for Health Statistics, lightning kills about 150 Americans each year and injures another 250. Lightning causes property losses about $150 million annually nationwide. At any given moment there are an estimated 1,800 thunderstorms over the earth's surface and lightning strikes the earth 100 times per second.
Actions When Outside
When a thunderstorm threatens, get inside a home or large building or inside an all-metal vehicle and not a convertible. Get out of the water and off small boats. Stay in your car if you are traveling. Cars offer excellent lightning protection.
In open areas, go to a low place such as a ravine or valley. Be aware of the possibility of flash flooding. Put down golf clubs and get to the nearest shelter. Do not stand under a tree. Lightning will strike at the tallest object in the area.
Actions When Inside
Inside the home, avoid using the telephone, except for emergencies, lightning can travel through the phone lines. This does not apply to cellular phones.