If you’re caught in a severe storm, your first priority is getting to shelter immediately, and your second is staying there longer than you think you need to. The specific actions that keep you safe depend on the type of storm and where you are when it hits. Here’s what to do in each scenario.
Lightning: The 30-30 Rule
Lightning is the most common severe weather killer that people underestimate, partly because thunderstorms feel routine. The National Weather Service recommends the 30-30 rule: when you see a flash of lightning, count the seconds until you hear thunder. If it’s 30 seconds or less, the storm is close enough to strike you. Get inside a substantial building or a hard-topped vehicle with the windows closed. If you can’t see the lightning, hearing thunder at all means you should take shelter.
The second “30” is the one people skip. Wait at least 30 minutes after the last flash of lightning before going back outside. Lightning can strike well ahead of or behind the visible storm, and many lightning deaths happen when people return outdoors too early.
If you’re caught in the open with no shelter available, avoid high ground, isolated trees, metal fences, and bodies of water. Crouching low with your feet together in a ditch or low spot is better than standing upright, though it’s not a substitute for real shelter.
Tornado Warnings: Where to Go
A tornado warning means a tornado has been spotted or detected on radar. You have minutes, not hours. Get to the lowest floor of the nearest sturdy building, then move to an interior room or hallway away from windows. Bathrooms and closets work because their small size and extra wall framing provide reinforcement. Cover your head and neck with your arms, a mattress, or heavy blankets. Flying debris is the primary cause of tornado injuries and deaths.
Purpose-built safe rooms are tested to withstand 250 mph gusts and resist penetration from a 15-pound board launched at 100 mph. If your home or workplace has one, use it. Stock it with a flashlight, first-aid kit, drinking water for at least eight hours, a fire extinguisher, and a weather radio. Underground shelters should also contain a signaling device so rescuers can locate you if debris blocks the entrance.
Mobile Homes Are Not Safe Shelter
Manufactured homes are built to withstand 70 to 110 mph winds depending on the wind zone, but tornado winds regularly exceed those thresholds. Even a relatively weak tornado can tear apart a mobile home. If a tornado warning is issued and you live in a manufactured home, leave immediately and go to a nearby permanent structure or a designated community shelter. This is one of the few situations where leaving your home during a storm is safer than staying.
Flash Floods: Turn Around, Don’t Drown
Moving water is far more powerful than it looks. Just 6 inches of fast-moving floodwater can knock an adult off their feet. Twelve inches can carry away most cars, and two feet of rushing water is enough to sweep away SUVs and trucks. These aren’t extreme scenarios. They happen in ordinary-looking road flooding after heavy rain.
Never drive through flooded roads, even if the water appears shallow. You can’t see the road surface beneath, and it may be washed out entirely. If your vehicle stalls in rising water, abandon it immediately and move to higher ground. Your car can be replaced.
If you’re on foot, stay off bridges over fast-moving water, avoid walking through any flowing water you can’t clearly see the bottom of, and move uphill. Flash floods can arrive with little warning, especially in canyons, dry creek beds, and urban areas where concrete prevents water absorption.
High Winds Without a Tornado
Severe thunderstorms and derechos can produce straight-line winds above 70 mph, strong enough to cause structural damage, tear off roof sections, and topple trees. If you’re indoors, move away from windows and exterior walls. Close interior doors to compartmentalize your home and reduce pressure changes if a window breaks.
If you’re driving, pull off the road into a safe parking area away from trees, power lines, and tall structures that could fall onto your vehicle. The shoulder of a busy highway is not a safe spot. A gas station lot, rest area, or parking garage is better. Keep your seatbelt on, turn off the engine, and stay below window level if debris is flying.
Cold, Wet, and Exposed
Storms don’t have to be violent to be dangerous. Prolonged exposure to rain, wind, and dropping temperatures can push your body toward hypothermia faster than most people expect, especially if your clothing is wet. Wind strips heat from your body much faster than still air, and wet fabric loses almost all its insulating ability.
Mild hypothermia begins when your core temperature drops below 95°F. Symptoms include intense shivering, clumsiness, and confusion. Moderate hypothermia (below roughly 90°F) brings slurred speech, slow breathing, and drowsiness. Severe hypothermia, below about 82°F, is a medical emergency where shivering actually stops and consciousness fades.
If you’re stranded outdoors in cold rain or wind, your priorities are shelter from wind, insulation from the ground, and getting dry. Even a makeshift windbreak from a tarp, vehicle, or rock formation makes a meaningful difference. Layer on any dry clothing you have, and keep moving enough to generate body heat without sweating, which would make you wet again.
After the Storm Passes
The period right after a severe storm is more dangerous than many people realize. Downed power lines are the biggest hidden threat. A fallen line can energize the ground up to 35 feet away, and you cannot tell by looking whether a line is live. Stay at least 10 feet from any downed line and anything it’s touching, including fences, tree limbs, and puddles.
If a power line falls on your car while you’re inside, stay in the vehicle. Honk your horn to get attention but tell anyone who approaches to stay away. The car’s tires insulate you from the ground. If you absolutely must exit because the car is on fire, jump out with both feet together so you’re never touching the car and the ground simultaneously, then shuffle away with small steps, keeping your feet close together to avoid creating a path for electricity to flow through your body.
Watch for other post-storm hazards: weakened trees and branches that can fall without warning, flooding that may still be rising even after rain stops, and structural damage to buildings that makes them unsafe to enter. If your home has visible damage to the roof or walls, don’t go inside until you’re confident the structure is sound.
Preparing Before Storm Season
The best thing you can do for severe storm survival happens before the storm arrives. Keep an emergency kit with at least one gallon of water per person per day for several days, a supply of non-perishable food, a flashlight with extra batteries, a battery-powered or hand-crank weather radio, a first-aid kit, and copies of important documents in a waterproof container.
Know your shelter plan for each type of storm. Identify the safest room in your home for tornadoes, know the elevation of your property relative to flood zones, and have a communication plan so family members know where to meet if separated. Program your phone to receive wireless emergency alerts, and pay attention when watches are issued. A watch means conditions are favorable for severe weather. A warning means it’s happening now.