Florida’s thunderstorms and tornadoes. What to know for Severe Weather Awareness Week

Florida Public Radio Emergency Network (FPREN) Storm Center | By Irene Sans

Severe Weather Awareness Week continues, and today, we’d like to highlight the hazards that severe thunderstorms bring when they develop. The main thing you must remember is that all storms have lightning or thunder. Otherwise, they are just showers. Although dangerous, lightning or thunder does not automatically make thunderstorms severe, nor does it prompt a severe thunderstorm warning by any National Weather Service office.

“The National Weather Service will conduct a Tornado Drill designed to evaluate where we would shelter if a tornado threatens our area. The tornado drill will be a great time to practice quickly getting to that safe place. On Wednesday, the drill will be broadcast over NOAA weather radios within Florida at 10 AM Eastern, 9 AM Central time. Participation is voluntary, but residents and businesses alike are encouraged to practice sheltering as if a tornado were threatening their area.” – FPREN Senior Meteorologist Megan Borowski

For a storm to become severe, it must have several more threats, such as damaging wind gusts and hail. The wind gusts must be at least 58 mph, and damage becomes possible at these speeds. Winds at these speeds could produce uprooted trees, broken tree branches, collapsed power lines, and minor roof damage. However, a low-category tornado can destroy mobile homes, patios, and pool enclosures.

Also, a severe thunderstorm warning can be issued when there is the possibility of at least quarter-sized hail. You might see specific wording in a warning issued by the National Weather Service or by one of us meteorologists at the Florida Public Radio Emergency Network; if a severe thunderstorm warning is labeled “considerable,” then the wind gusts are at least 70mph, or there is the threat for golf ball sized hail.

Did you know that Florida ranks 5th nationally in the annual average number of tornadoes and ties for 6th in tornado fatalities, with an average of 4 deaths yearly?

The National Weather Service can also issue a tornado watch when conditions are favorable for development and a warning when a tornado has been detected visually by a trained spotter or on radar. After a tornado, when there is damage, Meteorologists first look at the tornado damage and then estimate the wind speed that would have been needed to cause the damage. National Weather Service meteorologists use the Enhanced Fujita Scale, or EF Scale, to rate the strength of tornadoes based on the damage a storm produces.

Tornado tips

• Mobile homes are not a safe shelter for tornadoes.
• Stay inside, away from doors and windows.
• Bike helmets can provide excellent protection from flying debris.
• Remember to keep your shoes on if you have to shelter in place. If your home or neighborhood is damaged, you will eventually have to go outdoors, and being barefoot can put you in danger.
• It is best to take shelter in a basement — which most homes in Florida don’t have.
• If there is no basement, take shelter in your house’s lowest, most central room, away from windows and doors.

Tornadoes can’t be predicted, but meteorologists know when the weather conditions are favorable for the development of tornadoes. Not all thunderstorms spawn tornadoes, but severe thunderstorms spawn all tornadoes. It is best always to stay informed about the weather, especially when there is the threat of storms. If you feel the wind changing speed or direction, thunder roars. Remember, if you can hear thunder, you are close enough to be struck by lightning. When thunder roars, go indoors.

Another outlook you might see when there is a chance for severe weather

The local Weather Forecast Office of the National Weather Service office works locally and regionally. Still, the Storm Prediction Center, a National Weather Service division, also focuses on issuing severe thunderstorm alerts. Experts at the SPC monitor and forecast severe weather in the United States. The SPC’s mission is to provide accurate and timely forecasts and watches for severe weather, including tornadoes, thunderstorms, and wildfires. When a system can bring severe weather, the SPC issues alerts by categories: marginal, slight, enhanced, moderate, and high.

The NWS defines a severe thunderstorm as any storm that produces one or more of the following elements:

• A tornado.
• Damaging winds or speeds of 58 mph (50 knots) or greater.
• Hail 1 inch in diameter or larger.

The SPC further defines significant severe thunderstorms as any storm that produces one or more of the following elements:

• A tornado that produces EF2 or greater damage.
• Wind speeds of 75 mph (65 knots) or greater.
• Hail with a 2-inch in diameter or larger.

Tornadoes are more common in Florida than most might think. The state has experienced its fair share of catastrophic tornadoes, storms that have been bigger, longer in duration, and more intense, claiming the lives of dozens of people and destroying homes and other structures. Still, these storms are not as common as short-lived and small tornadoes that occur during the wet season, from May to October. These tornadoes are often classified as EF0 or EF1, with winds less than 110 mph.