Conditions are such that storms capable of producing a tornado may develop.
Move smaller objects indoors. Grills, bicycles, patio furniture, and lawn mowers can become missiles in tornadic winds and cause additional damage. Stay close to your TV or radio to see if a tornado warning is imminent. If you are in a mobile home or other location with no safe shelter, go to a public shelter when it begins to storm--don't wait until the sirens are sounded.
A tornado has either been sighted or it is highly probable that one will develop. A warning will be signaled by the storm warning sirens. (Take shelter immediately--it's too late to travel to a distant shelter.)