For a number of meteorological reasons, certain regions in the United States are especially ideal for the formation of violent thunderstorms and tornadoes. Because of this constant threat of severe weather, many homes in "Tornado Alley" feature an underground shelter known as a storm cellar. This shelter may be a rudimentary basement area with a sod floor, or it could be a finished shelter complete with food, water, and other survival essentials. A typical storm cellar is protected from the elements by a set of heavy doors placed at the top of a staircase.
The decision to leave home for the additional safety of a storm cellar may have to made very quickly, so much thought is given to the location of the shelter. Some homeowners place it directly under their houses for quick access. Others may choose to locate the shelter away from other structures to reduce the chance of storm debris blocking the doors. Drivers passing through rural areas of the Midwest and South may notice raised mounds of earth with ventilation pipes located near the edge of the road. These mounds are actually protecting an underground storm shelter.
Although a storm cellar may be a very rudimentary underground structure with minimal amenities, some manufacturers now market a more advanced form for those who wish to ride out a tornado or other severe weather in relative comfort. This type is typically formed by pressing a fiberglass and plastic material into a large form, much like the process used to make preformed swimming pools. The finished fiberglass shelter is carefully buried on the home owner's chosen site, and can be wired for electrical power. A preformed structure may feature comfortable seating for four, storage facilities for food and water, and space for a small television or radio.
An underground storm cellar is primarily designed to protect occupants from the type of damage created by tornadoes and severe thunderstorms. In the case of hurricanes, however, this type of shelter would not be the safest place to stay. Hurricanes often generate storm surges, which means low-lying areas may become flooded without much warning. A cellar could become a death trap during a hurricane-fueled storm surge. Evacuation to a safer location further inland would be preferable to waiting out the hurricane in a low-lying shelter.
