Tornadoes
Tornado damage from Hurricane Jeanne (2004) (mobile home, left) and
Hurricane Frances (2004) (brick home, right)
Tornadoes are one hazard from tropical cyclones that may catch many residents off-guard, especially since they are not usually accompanied by hail or a lot of lightning, clues that citizens often watch for. Although these tornadoes tend to be weaker and cause less damage than those spawned by other severe thunderstorms, it is important to make the public aware of this threat. About 4% of tropical cyclone deaths are caused by tornadoes.
Almost all tropical cyclones that hit the U.S. spawn at least one tornado, and some develop multiple ones. For example, Hurricane Ivan (2004) produced a tornado outbreak of 127 tornadoes over several days, continuing after the storm crossed the Alabama coast. Historically, many other hurricanes have been known to be prolific tornado producers.
Tornadoes can form with little or no warning, and we have no way at present to predict exactly which tropical cyclones will spawn tornadoes or where they will touch down. Doppler radar systems are the forecaster’s main warning tool, but the technology usually provides lead times from only a few minutes up to about an hour. Additionally, tornadoes can occur hundreds of miles from the center of a tropical cyclone. Consequently, preparedness and outreach is critical prior to the storm