Severe Storms risk in South Carolina

Severe Storms in South Carolina: What to Expect

Severe storms are a year-round fact of life in South Carolina, a state that sits in the warm, humid Southeast. The National Weather Service classifies a thunderstorm as severe when it produces wind gusts of at least 58 mph, hail that is 1 inch or larger, or a tornado. These storms can strike any county in the Palmetto State, but the likelihood is not spread evenly across the calendar or the map.

The Upstate and Piedmont region often sees strong afternoon thunderstorms from spring through late summer, fueled by heat and moisture moving inland from the Gulf of Mexico. The Midlands can experience squall lines that sweep across the state, while the Lowcountry and coastal counties are especially vulnerable to storms that move in from the Atlantic, including tropical systems that can bring tornadoes and damaging winds even after they weaken. In addition to wind and hail, severe thunderstorms in South Carolina frequently produce dangerous cloud-to-ground lightning and intense rainfall that can cause flash flooding in homes and neighborhoods.

Because of this combination of threats, the Federal Emergency Management Agency's National Risk Index gives South Carolina a severe storm risk rating of 4 out of 5, meaning the state has both a high likelihood of damaging storms and a high potential for losses. That rating should tell homeowners that severe storms are not just a seasonal inconvenience; they are a hazard to prepare for every year.

To keep up with an approaching storm, use a NOAA Weather Radio, a smartphone with Wireless Emergency Alerts, or the NOAA Storm Prediction Center outlooks. The National Weather Service Thunderstorm Safety page explains the difference between watches and warnings and recommends sheltering in an interior room, away from windows, when a tornado or high-wind warning is issued.

How it affects homes

Severe storms stress every part of a house. High winds can loosen or tear off roof shingles, pull off soffits, crack windows, and send lawn furniture or tree limbs through siding. Hail can be just as destructive, leaving dented metal roofs, broken skylights, and granule loss on asphalt shingles that shortens their lifespan. Lightning strikes can start structural fires or send power surges through electrical lines, destroying televisions, computers, and major appliances. Falling trees are another leading cause of home damage, and saturated ground from heavy rain makes trees more likely to uproot.

Heavy rainfall is a major hazard, too. A severe thunderstorm can drop several inches of rain in under an hour, causing water to pool around foundations, seep through basement walls, and back up through drains. Even if you do not live near a river, flash flooding can happen in poor-drainage neighborhoods, under highway overpasses, and in urban areas with lots of pavement.

For insurance, most standard homeowners policies cover damage from wind, hail, and lightning, but they do not cover flood damage. You will need a separate flood insurance policy, usually through the National Flood Insurance Program, to protect against water that enters from the ground. Many people do not realize this until after a storm, so it is important to check your policy now. It is also wise to ask your insurer about separate wind and hail deductibles, which can be higher than your standard deductible in some coastal areas.

How to prepare your home

Start with the parts of your home that are most exposed to storm damage. Keep roof shingles, flashing, and vents in good repair. If your roof is old or missing fasteners, review whether it is time for a replacement before the next storm season. Pay attention to your windows and doors, especially large sliders and double-entry doors; some homeowners use temporary plywood or pre-cut panels to protect glass when a severe storm is forecast.

• Trim back or remove dead, hanging, or diseased branches that could fall on your house, garage, or utility lines.
• Bring in or tie down outdoor furniture, grills, trash cans, potted plants, and children's toys when a storm is possible.
• Reinforce your garage door with a bracing system, because a damaged garage door can let destructive wind enter your home and lift the roof.
• Clean gutters and downspouts, and check that water drains at least 5 feet away from your foundation.
• Install a sump pump with a battery backup if you have a basement, crawl space, or a low-lying foundation.
• Use surge protectors for sensitive electronics, and consider having a licensed electrician install a whole-home lightning or surge protection system.
• Store important documents, such as insurance policies and home inventory lists, in a fireproof, waterproof safe or a secure cloud account.
• Create a family emergency plan with a safe room or an interior windowless room, and practice severe storm drills with everyone in your household.

Remember that no home can be made completely storm-proof, but these measures can reduce the risk of serious damage and help you recover more quickly. The South Carolina Emergency Management Division recommends building a supply kit with water, non-perishable food, flashlights, batteries, and a first-aid kit so that you are self-reliant for at least three days after a major storm.

Frequently asked questions

Does South Carolina get tornadoes?

Yes. Tornadoes are not as common or as large as the ones in the Midwest and Plains, but they occur in every part of South Carolina. They can happen at any time, especially in spring and fall, and they also form on the leading edge of squall lines and during tropical storms. Because tornadoes in the Southeast often move fast and may be rain-wrapped, you need to act quickly when a tornado warning is issued.

Does homeowners insurance cover severe storm damage?

Most standard homeowners policies cover the wind, hail, and lightning damage that severe storms cause. Flood damage from storm runoff, heavy rain, or rising water is not covered by standard policies, so a separate flood insurance policy is essential for many South Carolina homeowners. Your policy may also list special deductibles for wind, hail, or named storms, so review it with your insurance agent before you need to file a claim.

When is severe storm season in South Carolina?

Severe thunderstorms are most common in the spring and fall, but they can occur in any month. Summer brings frequent afternoon storms with lightning and downpours, while the autumn months see strong cold fronts that can trigger squall lines and tornadoes. The Atlantic hurricane season, June through November, adds the risk of tropical-storm-force winds and tornadoes, especially along the coast.

Official resources

• South Carolina Emergency Management Division
• NOAA Storm Prediction Center
• National Weather Service – Thunderstorm Safety
• Ready.gov – Thunderstorms and Lightning