(Adopted by AMS Council on 8 October 2004)
Bull. Amer. Met. Soc., 86
According to the American Housing Survey of the U.S. Census Bureau, approximately 20 million people permanently reside in an estimated 8 million mobile homes (now formally known as manufactured homes) throughout the country, representing about 8% of all homes in the United States . Of concern to the American Meteorological Society is that mobile home residents are injured or killed in disproportionate numbers from high wind events. For example, statistics kept by the National Oceanic and Atmospheric Administration’s (NOAA) Storm Prediction Center for the 18-year period from 1985 to 2002 show that 49% of the tornado fatalities in the United States are now suffered by those who remain within or attempt to flee mobile homes. Part of the problem associated with tornadoes and other severe windstorms is the flying debris resulting from damaged mobile homes, which may impact surrounding property.
The public perception that only tornadoes and hurricanes destroy mobile homes is wrong. These homes can be demolished by many kinds of severe winds. This includes thunderstorm outflows, cold fronts, midlatitude cyclones, and downslope winds off mountains. All of these can produce gusts in excess of 50 mph (measured over 3 seconds), which is approximately near the lower limit of wind speeds known to be capable of damaging mobile homes.
Stronger building codes are now in place in many states along the East and Gulf coasts and in Alaska, requiring new manufactured homes to withstand either 55 meters per second (120 mph, 3-second gust) or 58 meters per second (130 mph, 3-second gust) winds. Yet, there are still a large number of homes built before the early 1990s and outside these locales that need not meet this new standard and therefore are more vulnerable. Furthermore, as shown in the aftermath of Hurricane Andrew (1992), even the most rigorous building codes often are not well enforced.
Death, injury, and property damage in the wake of severe windstorms have prompted efforts to encourage owners of large mobile home communities to construct storm shelters. Such activity is considered essential for individual safety. Also, efforts at the local level to develop regulations governing mobile home anchors have proven effective as a property-protection measure in wind-prone areas.
To reduce the threat of death, injury, and property damage, the American Meteorological Society urges that
- mobile home residents use installation instructions provided by home manufacturers to ensure that their homes are properly anchored;
- mobile home residents become familiar with the emergency procedures that they should follow in the event of severe weather, since injuries can occur during high wind events even when proper anchoring procedures have been used;
- residents be prepared to immediately evacuate the dwelling and seek a storm shelter in the event of a tornado, severe thunderstorm, or high wind warning; and
- adequate wind-resistant shelters be constructed in all mobile home communities.
When mobile homes are moved, and/or if the manufacturer’s installation and anchoring instructions are not available, information on proper anchors and shelters may be obtained from state emergency services agencies, the Federal Emergency Management Administration (FEMA --- (http://www.fema.gov), and corporations specializing in mobile home tie-down equipment and installation. Appropriate government agencies are urged periodically to distribute relevant information to residents of mobile homes, such as procedures to follow in the event of severe weather and information on the construction of anchors and shelters. Warning sirens or some other local notification system would prove useful to alert residents of impending wind danger. Clearly visible signs should direct residents and visitors to any available shelters. Residents should purchase a NOAA weather radio. Timely severe weather updates also can be obtained from the commercial weather industry along with local radio and television media.
[This statement is considered in force until September 2013 unless superseded by a new statement issued by the AMS Council before this date.]