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How do you know when a tornado is coming?

When severe thunderstorms are forecast, stay alert for signs of an approaching tornado. Knowing what to look and listen for can help you get to safety before the tornado strikes.

Look for these visual clues of an approaching tornado:

  • Dark, greenish sky – The sky may take on a dark or greenish color as a tornado containing heavy rain, hail, and debris approaches.
  • Wall cloud – A rotating wall cloud forms on the underside of a supercell thunderstorm. Wall clouds often spawn tornadoes.
  • Funnel cloud – A visible funnel extending down from the wall cloud may signify that a tornado is forming.
  • Debris cloud – Look for a debris cloud near the base of the funnel. This means the tornado is tearing things up at the surface.
  • Large hail – Tornadoes are spawned from powerful thunderstorms and large hail is common with tornadic activity.

Listen for these audio warnings of a potential tornado:

  • Loud, continuous roar – The tornado winds produce a roar like a freight train.
  • Rushing air sound – Prior to forming a funnel, there may be a distinctive “whooshing” sound.
  • Quick increase in wind – The wind may begin blowing more strongly ahead of the tornado.
  • Sudden stillness – Some report a sudden quiet before the tornado hits as winds die down in the calm center of the twister.
  • Funnel clouds are spinning columns of air and condensed water droplets extending from the base of the thunderstorm cloud towards the ground. They do not always reach the surface. Tornadoes are violently rotating columns of air extending from the base of a thunderstorm cloud all the way to the ground. The intense winds can cause extensive damage where the tornado forms a narrow path along the ground.

Be prepared when a tornado warning is issued:

A tornado warning means a tornado has been sighted or is strongly indicated by weather radar. When a tornado warning is issued for your area, you should take shelter immediately:

  • If indoors, go to the centermost room on the lowest level of your home or office building. Stay away from windows and exterior doors.
  • If in a mobile home, immediately get to a sturdy shelter or an interior room of a well-constructed building.
  • If outdoors, get inside right away. If no shelter is available, lie down in a low area such as a ditch away from vehicles.
  • Do not try to outrun a tornado in your vehicle, leave it immediately for more secure shelter.
  • After the tornado passes, watch for fallen power lines and stay out of damaged areas.

Know the difference between a tornado watch and a tornado warning:

Tornado Watch Tornado Warning
A tornado watch means tornadoes are possible in the area. Remain alert for approaching storms. A tornado warning means a tornado has been sighted or indicated by weather radar. Take shelter immediately if one is issued for your area.

Sign up for your community’s warning system:

Many communities have tornado sirens and emergency alert systems. Sign up to receive warnings on your phone, email, or text to stay informed whenever tornadoes threaten.

Outdoor warning sirens

Outdoor warning sirens are meant to alert people who are outside that danger is approaching. If you hear a siren, go indoors and seek more details.

NOAA Weather Radio

A NOAA Weather Radio provides alerts directly from the National Weather Service. The special radios can wake you up when a warning is issued for your area.

Wireless Emergency Alerts

Emergency weather alerts can be sent as text messages to mobile phones in the path of the storm. This free service keeps you up-to-date wherever you are.

Have frequent tornado drills:

Practicing your emergency tornado plan regularly ensures everyone knows what to do if a tornado is approaching. Have drills at home, school, work, or other locations you frequent.

Make an emergency plan

Know where to take shelter if a tornado warning is issued and have several ways to receive alerts.

Prepare your home

Consider constructing a shelter or safe room and have emergency supplies on hand.

Practice the drill

Make sure everyone involved knows where to go and what to do in a tornado drill.


Being prepared is key to staying safe when tornadoes threaten. Know the warning signs, have a plan, take alerts seriously, and act quickly to get to sturdy shelter when a tornado strikes. Understanding tornado weather safety could save your life.