Severe thunderstorms cause more annual damage in the US than hurricanes in many years. They bring damaging winds (58+ mph), hail, lightning, and tornado spin-ups.
Before the Storm
- Charge phones and power banks
- Secure outdoor furniture and trash bins
- Trim dead branches overhanging the house
- Test NOAA weather radio
- Identify interior room on lowest floor (no windows)
During the Storm
- Go indoors immediately — "When thunder roars, go indoors"
- Avoid windows, porches, and garages
- Don't use corded phones or plumbing
- If driving, pull over away from trees and power lines — don't touch metal inside the car
- If a tornado warning is issued, move to interior room or basement
Power Outage Response
- Report downed power lines — assume they are live
- Keep refrigerator closed (4-hour food safety window)
- Use battery lights instead of candles when possible
Full guide: Power Outage Survival Guide
Understanding Severe Thunderstorm Risks
A thunderstorm becomes "severe" when it produces hail ≥1 inch, wind gusts ≥58 mph, or a tornado. Straight-line derecho winds can down trees across a 200-mile path — knocking out power to millions for days. In 2020, a derecho caused an estimated $11 billion in damage across the Midwest alone.
Lightning kills an average of 20–30 Americans per year. Strikes can occur 10 miles from rainfall — blue sky overhead does not mean safety.
Regional Prep Differences
| Region | Primary thunderstorm risk | Key prep focus |
|---|---|---|
| Midwest / Plains | Tornadoes, derechos | Basement shelter, NOAA radio |
| Southeast | Lightning, flash floods | Elevated storage, drainage |
| Northeast | Downed trees, outages | Generator safety, chain saw readiness |
| Southwest | Dry lightning, wildfire ignition | Defensible space, evacuation routes |
Home Hardening Checklist
- Install surge protectors on electronics — whole-house surge devices protect HVAC and appliances
- Trim branches within 10 feet of roof lines
- Secure patio furniture before storm season (March–April in most regions)
- Label electrical panel circuits now — you'll need this in the dark
- Store a battery-powered NOAA radio in the kitchen, not the garage
Tornado Spin-Up Warning Signs
Severe thunderstorms can produce tornadoes with little warning. Watch for:
- Greenish-black sky color
- Wall cloud or rotating cloud base
- Hail followed by dead calm
- Loud continuous roar (not individual thunder claps)
If observed, move to the lowest interior floor immediately. See our Severe Thunderstorm Prep guide.
After the Storm
- Inspect roof and siding for hail damage (document for insurance)
- Restock used batteries and power banks
- Check on neighbors, especially elderly residents
Bottom Line
Severe thunderstorms are short but violent. A charged radio, interior shelter plan, and power backup handle most scenarios.
❓ Frequently Asked Questions
- What is the difference between a watch and a warning?
- A Severe Thunderstorm Watch means conditions are favorable. A Warning means a storm is happening or imminent — take shelter now.
- Is it safe to shower during a thunderstorm?
- Avoid plumbing and wired electronics — lightning can travel through pipes and wiring. Unplug sensitive devices.
- How long do severe thunderstorms last?
- Individual cells last 30–60 minutes, but squall lines can produce hours of damaging winds and outages across multiple states.