AccuWeather.com

By Jillian MacMath, AccuWeather.com Staff Writer

Apr 15, 2012; 6:50 PM ET

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Photo by Victor Zastol`skiy of photos.com

Though everyone has seen a Hollywood tornado flick where a highway overpass has served as an effective shelter against an F-5 twister, officials say it's certainly not the recommended course of action.

Similarly, Americans have held on to various other myths causing them to act dangerously and incorrectly in the face of a volatile tornado. Compiled below are five of the top myths debunked to help keep you safe and sound should you find yourself in a Helen Hunt-esque scenario.

1. Opening windows during a tornado will relieve pressure and save a house from destruction

Opening windows during a tornado provides no benefits. Though tornadoes are caused by intense pressure, merely opening windows will not alleviate or equalize this. Because of the intense power of a tornado, it is best to seek shelter underground in a basement, or in a room with no windows altogether. Opening them only creates a portal through which more debris can enter your home.

2. Seeking shelter under a highway overpass will protect you from a tornado

Though everyone has seen a movie where the characters wait out a tornado under a highway overpass, as the phrase goes, "it's only a movie." According to the National Weather Service Forecast Office, "Seeking shelter under an overpass is more dangerous than standing in an open field while a tornado is approaching." When a tornado passes over an overpass, the wind is funneled under the bridge. In turn, this actually increases its velocity.

Additionally, overpasses are often where debris tends to collect. The safest option is to lie flat on the ground in a low ditch, but beware of the possibility of flash flooding.

3. A green sky is an indicator that a tornado is coming

The green sky phenomenon has been puzzling scientists for decades. It has not been disproved that a green sky is an indicator of a developing tornado, but it's not a sure-fire sign either. There are a number of theories of why this could occur.

In some cases, green clouds can appear in thunderstorms that are dropping hail and other times the cause may be as benign as the way in which the light particles from the reddish setting sun hit the blue clouds. Either way, it is dangerous to believe that the color of any cloud will tell you whether a tornado is approaching. Heed all warnings.

4. Tornadoes do not strike in cities

Though tornadoes are known to strike in the plains more often than cities, they know no bounds. Tornadoes have the ability to develop anywhere. The reason they more frequently develop in open land, however, is simply because cities are small. In the U.S., the percentage of suburban space is significantly greater than that of urban space. Additionally, states in the South and Midwest, including the 'Tornado Alley', have more favorable conditions for tornadoes and also contain fewer cities.

5. Taking cover in the southwest corner of your house will protect you from a tornado

This theory was published originally in 1887 by American meteorologist John Park Finley. Finley advised that people should "under no circumstance" take shelter in a northwest corner of a room or basement. His theory stemmed from the myth that because tornadoes typically come from the southwest, debris will tend to be blown to the northeast side. This information was then distributed in various newspapers and became conventional wisdom.

But, as it turns out, Finley was incorrect. Debris, such as walls, floors and furniture can be blown to any corner of a house. According to Roger Edwards of the Storm Prediction Center, "Tornadoes are not straight-line winds, even on the scale of a house, so the strongest wind may be blowing from any direction and tornadoes themselves may arrive from any direction."