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Tornadoes & Waterspouts
Tornadoes can form with little to no warning and it is important that every individual is prepared for such an event. When a tornado is imminent, there is only a short amount of time to act. Advance planning and quick response are the keys to surviving a tornado.
Florida's Tornado Season
- Summer season, from June until September, has the highest frequencies with usual intensities. This includes those tornadoes that form from land during tropical cyclones.
- Spring season, from February through April, is characterized by more powerful tornadoes because of the presence of the jet stream. When the jet stream digs south into Florida and is accompanied by a strong cold front and a strong squall line of thunderstorms, the jet stream's high-level winds of 100 to 200 mph often strengthen a thunderstorm into what meteorologists call a supercell or mesocyclone. These powerful storms can move at speeds of 30 to 50 mph, produce dangerous downburst winds, large hail, and the most deadly tornadoes.
When Tornadoes are Likely to Strike
Florida tornado climatology shows us that strong to violent tornadoes are just as likely to occur after midnight as they are in the afternoon. This unique feature makes these tornadoes more dangerous because most people are asleep after midnight and cannot receive weather warnings relayed by commercial radio or television stations.
The solution to this is to have a NOAA Weather Radio or alert system set on a cell phone with a tone alert feature. This will allow you to receive warnings issued by your local National Weather Service office.
During a Tornado
- Go to a windowless interior room, like a bathroom or closet.
- Go to the center of the room and stay away from corners because they tend to attract debris.
- Go under a piece of sturdy furniture, like a workbench or heavy table, and hold on, or use your arms to protect your neck and head.
- Gather emergency supplies and listen to a local radio or television station for further information.
If You Live in a Mobile Home
Mobile homes are particularly vulnerable. Do not remain in a mobile home if a tornado is approaching. Predetermine safe shelter areas. When a tornado watch is issued, take shelter in a building with a strong foundation. If not, lie in a ditch or low-lying area a safe distance away from the mobile home.
If You are in a Car
Leave the vehicle immediately for safe shelter. Do not seek shelter in an overpass or bridge. If caught outside or in a vehicle, get inside a nearby building if you can, or lie flat in a nearby ditch or depression and cover your head and arms.
How to Prepare for Tornadoes
- Build or identify a safe-room in your home
- Purchase and use a NOAA Weather Radio
- Learn how to protect yourself during a tornado
Waterspouts are weak tornadoes that form over warm water. Two major ingredients of the atmosphere for a waterspout to form are warm air temperatures and high humidity level. The islands and the shallow water along them help heat the air. During the summer, the air is extremely humid with temperatures in the mid-80s and low 90s. The heat causes the air to rise. As it rises, the air’s humidity condenses into the tiny water droplets that make up clouds. As water vapor condenses, it releases more heat that makes the air rise even faster. Rising air currents are needed for waterspout formation.
An important ingredient in the Keys is the regular east or northeast “trade winds” that blow right down the islands. Waterspouts tend to come from clouds with a dark, flat bottom when there is just a hint of rain. Waterspouts are most common along the Gulf Coast and southeastern states. In the western United States, they occur with cold late fall or late winter storms, during a time when you least expect tornado development. Waterspouts occasionally move inland becoming tornadoes, causing damage and injuries. Even though waterspouts are usually weaker than strong tornadoes over land, they can be a real danger to boaters.