Thunderstorms

Many of us love thunderstorms and lightning — as long as we are in a safe place to witness the spectacle! Storms are beautiful, humbling, awe-inspiring, exciting, comforting, and they can create an amazing light show, here on Amelia Island.

There are three things you need for a thunderstorm to form: moisture, atmospheric instability (temperature and density), and movement. In the heat of the summer, water enters the atmosphere through evaporation and transpiration from plant surfaces, which starts to fuel a thunderstorm.

The sun heats the ground and surface water, warming the air near the earth, causing a heat and density gradient. Warm pockets of air start to rise, colliding with cooler air, causing static electricity and friction. As the warm air rises into the atmosphere, it cools and condenses, creating rain and often hail. Hail forms when the updraft of wind carries water droplets upward into the freezing atmosphere. This can happen over and over again, creating very large hail.

The friction and electron transfer in these collisions result in a heavily polarized cloud. Within that polarized cloud, lightning discharges energy with an electric charge of 300 million volts.

According to NOAA, when the surrounding air is superheated to 30,000 C, it expands explosively. When it cools just as fast, it contracts and rushes inward, creating a vacuum that produces an acoustic shockwave. This rapid expansion and contraction is exactly what you hear as thunder.

We are fortunate that thunder is a built-in warning system; never underestimate the danger of lightning. In Fernandina Beach, we have an additional warning system called Thor Guard. The Thor Guard equipment measures and analyzes the atmospheric field in real time at different locations around the city, and is paired with audible warning systems. Thor signals one long blast for lightning in the area, take shelter, and three short blasts for the all clear back to normal. Thor Guard has a real-time mobile app for the public.

If you cannot hear Thor, you can estimate the distance lighting is from your location by counting seconds. This is an accurate calculation and an appropriate tool to use.

Calculation: Secs/5 = distance in miles (the lightning is away from you)

Example: 10 Secs/5 = 2 miles 

The sound from the lightning travels one mile every 5 seconds. When you hear thunder, you are in potential danger and should go indoors. As a general rule, staying sheltered for 30 minutes after you hear the last lightning strike is considered wise.

In Florida, there are 7-10 fatalities a year and dozens of injuries. Florida is the lightning capital of the United States. You are significantly more likely to get struck by lightning than get bitten by a shark, even in Florida.

Just this June, an 18-year-old named Michael Vargas lost his life from a lightning strike while kayaking with his dad. They were kayaking in Santa Rosa County on the Blackwater River.

Katherine Diaz Hernandez, a future Olympic surfer, was killed by lightning on the beach on March 19, 2021. The young woman was struck while entering the water to train for the ISA World Surfing Games and the Olympics; she was just 22 years old. The unexpected strike occurred despite the day initially being sunny at El Tunco Beach, a popular surfing destination on the Pacific coast.

Here on the First Coast, we can stay safe during the lightning-prone summer months by watching the radar, weather alerts on your phone, watching the sky, timing your outings appropriately, wearing shoes, and looking for safety zones in case you get stuck outside during a storm. Avoid using water in the home regardless of what type of plumbing you have, and unplug electronics. Do not drive in a “white out” rain storm, do not shower outside when lightning is present, stop golfing, running, surfing, and boating, and seek shelter!

If you encounter a lightning strike victim, call 911.