The following is a copy of advise provided by the FEMA regarding thunderstorms:
What to Do Before a Thunderstorm
To prepare for a thunderstorm, you should do the following:
Remove dead or rotting trees and branches that could fall and cause injury or damage during a severe thunderstorm.
“If thunder roars, go indoors” because no place outside is safe when lightning is in the area. We want everyone to stay indoors until 30 minutes have passed after they hear the last clap of thunder.
Summary of Lightning Safety Tips for Inside the Home
Avoid contact with corded phones
Avoid contact with electrical equipment or cords. If you plan to unplug any electronic equipment, do so well before the storm arrives.
Avoid contact with plumbing. Do not wash your hands, do not take a shower, do not wash dishes, and do not do laundry.
Stay away from windows and doors, and stay off porches.
Do not lie on concrete floors and do not lean against concrete walls.
The following are guidelines for what you should do if a thunderstorm is likely in your area:
Postpone outdoor activities.
Get inside a home, building, or hard top automobile (not a convertible). Although you may be injured if lightning strikes your car, you are much safer inside a vehicle than outside.
Remember, rubber-soled shoes and rubber tires provide NO protection from lightning. However, the steel frame of a hard-topped vehicle provides increased protection if you are not touching metal.
Secure outdoor objects that could blow away or cause damage.
Shutter windows and secure outside doors. If shutters are not available, close window blinds, shades, or curtains.
Avoid showering or bathing. Plumbing and bathroom fixtures can conduct electricity.
Use a corded telephone only for emergencies. Cordless and cellular telephones are safe to use.
Unplug appliances and other electrical items such as computers and turn off air conditioners. Power surges from lightning can cause serious damage.
Use your battery-operated NOAA Weather Radio for updates from local officials.
Avoid the following:
Natural lightning rods such as a tall, isolated tree in an open area.
Hilltops, open fields, the beach, or a boat on the water.
Isolated sheds or other small structures in open areas.
Anything metal—tractors, farm equipment, motorcycles, golf carts, golf clubs, and bicycles.
You can view the article at: http://www.fema.gov/hazard/thunderstorm/th_before.shtm