Thanks to the unique geography of North America ”“ where polar air from Canada, moist tropical air from the Gulf of Mexico and dry air from the American Southwest meet to produce intense thunderstorms ”“ an estimated 1,000 tornadoes occur in the United States each year, more than any other country in the world.

Tornadoes can take almost any shape and size. They can strike one at a time or in clusters; they can leave a path of destruction 50 yards wide, or more than a mile wide; they can touch down for a matter of seconds, or they can remain in contact with the ground for an hour or more.

When & Where Are Tornadoes Most Likely?

In the U.S., the most active time of the year for tornado activity ”“ commonly referred to as "tornado season" -- typically falls between April and July, with May and June usually the peak months. Many of those tornadoes strike in the region known as "tornado alley," which stretches across the Plains states from northern Texas to Nebraska.

Like the thunderstorms that spawn them, however, tornadoes are possible at any time of year and in any part of the country. Though in many cases advance warnings can be issued for tornadoes, it is important to be aware that tornadoes can change direction, speed and intensity very quickly.

Some tornado facts to keep in mind:

• Tornadoes usually accompany thunderstorms, but not always.
• Sometimes the air is calm before a tornado hits, while in other cases it is preceded by strong, gusty winds.
• A tornado may follow sunshine or be shrouded in heavy rain and large, dark, low-lying clouds.
• The sound of a tornado has been compared to a freight train or a jet engine, but you may or may not hear such a noise before a tornado strikes.

Protect Your Family and Home

Make a plan to prepare and protect the people and things you value before severe weather strikes:

• Make sure your family members know and understand the siren warning signals, if there is such a system in place in your area.
• Take photographs of your valuables and store them in a fire- and waterproof safe. Also use the safe to store important documents such as birth certificates, ownership documentation for cars and boats, Social Security cards, insurance policies and wills.
• Check your homeowner's insurance to confirm your coverage in case your home is damaged or destroyed. Tornadoes can be accompanied by heavy rains and flooding, which most homeowner's insurance policies do not cover. Check with your insurance agent or the National Flood Insurance Program for more information.
• Assemble a family disaster kit.
• Locate and mark where utility switches and valves are in your home so they can be turned off in an emergency if time allows.
• Depending on your location, you may be told to evacuate before a warning or even a watch is issued. Notify friends and/or family members who are unaffected by the storm of where you're going and why.
• Familiarize yourself with the emergency action plans at your school or workplace and identify the appropriate officials and emergency management agencies in your area, with contact information and phone numbers in case you need assistance after a storm.
• Make sure to charge your mobile phone, laptop and other mobile device batteries.

Stay Alert for Storms

To ensure you receive all of the latest weather updates during a severe thunderstorm, you'll need more than one reliable source of weather information. We recommend the following:

• Sign up for The Weather Channel Alerts for your mobile phone and/or email. Receive all our alerts by signing up here.
• Purchase a NOAA Weather Radio, which broadcasts all of the latest weather updates as well as storm watches and warnings for your area. Learn more at the NOAA Weather Radio site.
• Make sure you have fresh batteries for your radio(s) and flashlights, in case your home loses power for an extended period of time.
• Learn the difference between a severe thunderstorm watch and warning as well as a tornado watch and warning.

Family Preparedness Plan

Develop a disaster preparedness plan for your family that includes the following:

• A place to go if necessary when a tornado watch or warning is issued, depending on where you are ”“ at home, school, work, or if you're outdoors or in your car.
• Plan for a friend or relative you've designated as your point of contact if you are separated from your family during a severe thunderstorm.
• Place where family members can meet if you're separated after a tornado strikes.
• Names and contact information for your insurance agents, including policy types and numbers.
• Telephone numbers for your utility providers, including gas, water and electricity.