Get inside a sturdy building. If no such shelter is avaliable, get into or stay in a hard-topped vehicle (not a soft top vehicle like a convertible). This is better than being outside.
Remember, rubber soled shoes and rubber tires provide NO PROTECTION from lightning
Secure outdoor objects that could blow away or cause damage
Shutter windows and secure outside doors. If shutters are not avaliable, close window blinds, shades, or curtains.
Avoid showering or bathing. Plumbing and bathroom fixtures can conduct electricity.
Do not use telephones during severe storms unless it is a life-threatening emergency
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
Never walk, wade, or drive through flooded areas
Treat all wires lying on the ground or tangled in trees as energized and EXTREMELY dangerous
Call 911 only if it is a life threatening emergency and you immediately need police, fire, or EMS assistance