A tornado is a violent windstorm characterized by a twisting, funnel-shaped cloud. It is spawned by a thunderstorm (or sometimes as a result of a hurricane) and produced when cool air overrides a layer of warm air, forcing the warm air to rise rapidly. The damage from a tornado is a result of the high wind velocity and wind-blown debris. Tornado season is generally March through August, although tornadoes can occur at anytime of year. They tend to occur in the afternoons and evenings (over 80 percent of all tornadoes strike between noon and midnight). Tornadoes can occur in any state but are more frequent in the Midwest, Southeast and Southwest. The states of Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana, Mississippi, Missouri, Nebraska, Oklahoma, South Dakota, and Texas are at greatest risk.
Tropical Storm Conditions:
- Condition V (Seasonal):Maintained throughout the Atlantic Region 1 Jun-30 Nov
- Condition IV (Alert): Indicates a possible tropical storm within 72 hrs
- Condition II(Alert): Destructive winds 50+kits are anticipated within 48 hrs
- Condition I (Emergency): Destructive winds are in the area or anticipated within 12 hrs
Emergency Operation Center Expectation:
Prior to 01 June
- Develop Family Plan
- Identify items to be taken with you
- Prepare disaster kit
At Condition V:
- Review command procedures
At Condition IV:
- Top off gas tank
- Ensure you have emergency money on hand
- Start packing for evacuation
- Move all items inside you home such as lawn furniture and toys
At Condition III:
- Evacuate orderly when ordered by the command
At Condition II:
- To recall an shelter all CAT1 and CAT5 personnel including Dependents
At Condition I:
- Stand by for major hit
Damage Estimates. The following can be expected based upon each of the six tornado types.
Condition | Winds | Predicted Damage |
F-0 | 40 - 72 | Chimney damage, tree branches broken. |
F-1 | 73 - 112 | Mobile homes pushed off foundation or overturned. |
F-2 | 113 - 157 | Considerable damage, mobile homes demolished, trees up rooted. |
F-3 | 158 - 205 | Roofs and walls torn down, trains overturned, cars thrown. |
F-4 | 207 - 260 | Well-constructed walls leveled. |
F-5 | 261 - 318 | Homes lifted off foundation and carried considerable distances, autos thrown as far as 100 meters. |