Two words, two completely different responses
The National Weather Service uses a deliberate two-tier alert system. A watch means conditions are favorable for the hazard to develop. The Storm Prediction Center issues watches across large areas, sometimes spanning multiple states, typically lasting four to eight hours. A watch is your window to prepare.
A warning means the hazard has been detected or is imminent. Local NWS forecast offices issue warnings for much smaller areas (a county or part of a county) with much shorter durations, often 20 to 60 minutes. A warning is not the time to prepare. It is the time to act.
This two-tier structure applies to tornadoes, severe thunderstorms, floods, and winter storms. The average tornado warning lead time is about 13 to 15 minutes. Some fast-developing storms give only a few minutes. That is why the shelter plan needs to be decided during the watch, not debated during the warning.
During a watch: review your shelter plan with everyone in the household. Charge phones and power banks. Gather shoes, flashlights, and medications near the shelter area. Bring pets inside. Monitor alerts on multiple channels: phone, NOAA Weather Radio, local media.
Lowest floor, interior room, away from windows
NWS, Ready.gov, and the Red Cross all converge on the same guidance. When a tornado warning is issued, go immediately to a basement, storm cellar, or safe room if one exists. If none is available, move to a small interior room on the lowest floor, away from all windows. Bathrooms and closets along interior walls are the standard fallback.
Protect your head and neck. Cover yourself with arms, a heavy blanket, a mattress, or a bicycle or motorcycle helmet if one is available. Most tornado injuries come from flying debris, not building collapse. Head protection is the single highest-value action after getting to the right location.
Close interior doors as you move through the house. Each closed door is a barrier that slows wind and debris penetration. Do not open windows. The old belief that equalizing pressure prevents structural damage is incorrect. Opening windows wastes time and allows wind and rain inside.
Mobile homes are not safe in any tornado, even one rated EF-0. NWS guidance is clear: leave the mobile home and go to a nearby sturdy building. If no building is available, lie flat in a low area (a ditch or depression) and cover your head. Do not shelter under a highway overpass. Wind speeds increase in the constriction, and there is no protection from debris.
- Watch: conditions favorable. Prepare. Review plan, charge devices, gather supplies near shelter.
- Warning: tornado detected or imminent. Act now. Go to shelter immediately.
- Shelter: basement or interior room, lowest floor, away from windows. Close doors behind you.
- Protect your head with arms, blanket, mattress, or helmet.
- Do not: open windows, shelter under an overpass, or stay in a mobile home.
- Average warning lead time: 13-15 minutes. Some storms give less.
- Tornado Safety: During a Tornado — National Weather Service. Shelter location, head protection, mobile home guidance.
- Watches and Warnings — NWS. Definitions, issuance criteria, lead times.
- Tornadoes — Ready.gov / FEMA. Household planning, shelter guidance, watch vs warning actions.