Enhanced Fujita Scale
|EF-Scale:||Old F-Scale:||Typical Damage:|
|EF-0 (65-85 mph)||F0 (65-73 mph)||Light damage. Peels surface off some roofs; some damage to gutters or siding; branches broken off trees; shallow-rooted trees pushed over.|
|EF-1 (86-110 mph)||F1 (73-112 mph)||Moderate damage. Roofs severely stripped; mobile homes overturned or badly damaged; loss of exterior doors; windows and other glass broken.|
|EF-2(111-135 mph)||F2 (113-157 mph)||Considerable damage. Roofs torn off well-constructed houses; foundations of frame homes shifted; mobile homes completely destroyed; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground.|
|EF-3 (136-165 mph)||F3 (158-206 mph)||Severe damage. Entire stories of well-constructed houses destroyed; severe damage to large buildings such as shopping malls; trains overturned; trees debarked; heavy cars lifted off the ground and thrown; structures with weak foundations blown away some distance.|
|EF-4 (166-200 mph)||F4 (207-260 mph)||Devastating damage. Whole frame houses Well-constructed houses and whole frame houses completely leveled; cars thrown and small missiles generated.|
|EF-5 (>200 mph)||F5 (261-318 mph)||Incredible damage. Strong frame houses leveled off foundations and swept away; automobile-sized missiles fly through the air in excess of 100 m (109 yd); high-rise buildings have significant structural deformation; incredible phenomena will occur.|
|EF No rating||F6-F12 (319 mph to speed of sound)||Inconceivable damage. Should a tornado with the maximum wind speed in excess of EF-5 occur, the extent and types of damage may not be conceived. A number of missiles such as iceboxes, water heaters, storage tanks, automobiles, etc.will create serious secondary damage on structures.|
Tornado Safety Rules
We can do little to prevent a tornado from occurring, but by knowing the safety rules we can minimize the number of deaths and injuries.
A tornado watch means that tornado development is possible. Keep a watchful eye on the sky for threatening weather and stay tuned to radio and television and listen for weather bulletins.
A tornado warning means that a tornado has been sighted or indicated by radar. Persons in the path of the storm should seek shelter immediately - preferably in a storm cellar, underground excavation, or in a steel-framed or concrete reinforced building.
A severe thunderstorm warning means that either spotters or radar have indicated that severe weather is occuring, and is expected to be heading towards you soon. This warning is issued by the National Weather Service local office, and usually covers a few counties, lasting about an hour or so. A thunderstorm is classified as severe because it can contain hail three-quarter inches or larger, and/or wind gusts of 58 mph or higher, and/or a tornado. When a warning is issued, persons should remain indoors until the storm has passed.
In homes,the basement offers the greatest safety. Seek shelter under sturdy furniture if possible. In homes without basements take cover in the center part of the house, on the lowest floor, in a small room such as a closet or bathroom, or under sturdy furniture. Stay away from windows!
In schools, hospitals, and shopping centers move to pre-designated shelter areas. Interior hallways on lowest floors are best. If the building is not of reinforced construction, go to a nearby one that is, or take cover outside on low, protected ground. Stay out of auditoriums, gymnasiums, and other structures with wide free-span roofs.
In open country, move away from the tornado's path at right angles. If there is not time to escape,lie flat in the nearest ditch or ravine.
In your car, do not try to outrun a tornado. If available take shelter in a sturdy structure. Otherwise, get in the nearest ditch or depression until the tornado passes.
Mobile homes are particularly vulnerable to overturning during strong winds and should be evacuated when strong winds or tornadoes are forecast. Damage can be minimized by securing trailers with cables anchored in concrete footing. Trailer parks should have some community storm shelters. If there is no shelter nearby, leave the trailer park and take cover on low-protected ground.