Tornadoes can occur with little warning. Here are tips to help you prepare and survive in case disaster strikes.

Watch vs. warning:

— A tornado watch means that weather conditions are favorable for severe thunderstorms or tornadoes to develop.

— A tornado warning means that a tornado has actually been sighted. A warning is the more serious of the two; take shelter immediately.

— Some signs that signal an approaching tornado include: a dark or greenish sky, large hailstones and a loud roar that sounds like a freight train.

Rebecca Callahan of the American Red Cross describes what items are needed for a preparedness kit and what to do in an emergency. (Jayne Orenstein/The Washington Post)

Plan ahead:

— Secure furniture with brackets or eyebolts, arrange chairs and beds away from windows, and place large or heavy items on low shelves.

— Assemble a first-aid kit and emergency supplies, including water, non-perishable food, a flashlight with extra batteries and a portable radio.

— Make copies of essential documents, such as IDs, insurance policies and financial records.

— Know how to turn off the gas, water and electricity in your home.

During a tornado:

— Find shelter, preferably a basement or other underground, windowless space. If a basement isn’t available, go to a room with no windows on the lowest level of the building.

— Avoid windows.

— Use a heavy blanket or sleeping bag to protect your body and body from debris. Head injuries are a common cause of death during tornadoes; helmets can provide extra protection but are not an alternative to shelter.

— If outdoors or in a moving vehicle, try to find shelter indoors or in a ditch. Do not try to outrun a tornado in your car. Lie flat and cover your head with your arms.

After a tornado:

— Check for injuries and damage that require immediate attention.

— Use your portable or car radio for additional information and safety advisories. Use the telephone for emergencies only.

— Contact your insurance provider to report damage and begin the claims process.

— Use caution during rescue attempts and cleanup. Wear sturdy shoes, and be aware of hazards such as exposed nails, broken glass, down power lines.

— Anxiety and fear are common in the days, weeks and months following the tornado. Monitor yourself and others, especially children, and seek professional help if anxiety disrupts daily activities.

Sources: Alexandria Fire Department (also En Espanol ); Centers for Disease Control and Prevention