A tornado is a narrow, violently rotating column of air that extends from a thunderstorm to the ground. Because wind is invisible, it is hard to see a tornado unless it forms a condensation funnel made up of water droplets, dust and debris. Tornadoes can be among the most violent phenomena of all atmospheric storms.

Tornado behavior in California is different than in the Mid-west due to several factors including our topography and moisture content not being hot and humid. This also means that tornados are shorter in duration and intensity than those seen in the Mid-west as well as much more rare.


Tornado Watch

A tornado watch means that a tornado is possible. A tornado watch is issued when weather conditions favor the formation of tornadoes.

Actions you should take if there is a Tornado Watch:

Tornado Warning

A tornado warning means that a tornado has been sighted or indicated by weather radar. 

Actions you should take if there is a Tornado Warning:

Tornado Signs

Tornados in California strike quickly, often without time for a tornado watch or warning, so it is important to know the signs of a tornado. 

Signs that a tornado may be approaching include the following:

  • Rotating funnel-shaped cloud
  • Approaching cloud of debris
  • Dark or green-colored sky
  • Large, dark, low-lying cloud
  • Large hail
  • Loud roar that sounds like a freight train

If you notice any of these signs take cover immediately and stay tuned to local radio and TV stations, a NOAA weather radio, your cell phone or the internet.

Tornado Warning Notification Process

The National Weather Service will issue a Wireless Emergency Alert and an Emergency Alert System message whenever a Tornado Warning is issued. However, in California (due to how tornados occur so differently than in the Mid-west) it is rare for a Tornado Warning to be able to be issued before a tornado happens, so most tornados in California will be a no notice event.

Be prepared and stay aware during thunderstorms. 

Make a Tornado Plan

Creating your tornado plan is similar to planning for other emergencies we may face:

  • Identify a safe place in your home for household members and pets to gather during a tornado
  • Sketch a floor plan of your home or walk through each room and discuss where and how to seek shelter
  • Identify a second way to exit from each room or area
  • Note where your first-aid kit and fire extinguishers are located
  • Note where the utility switches or valves are located so they can be turned off (if time permits) during an emergency
  • Make sure everyone understands tornado warning signs
  • Teach your family how to administer basic first aid, how to use a fire extinguisher, and how and when to turn off water, gas, and electricity in your home
  • Keep your emergency supply kit ready
More Questions?

NOAA FAQs about Tornados

Straight-Line Winds 

When tornados are discussed often straight-line winds are also mentioned. Straight-line winds is a term used to define any thunderstorm wind that is not associated with rotation, and is used mainly to differentiate from tornadic winds.

What's the difference between a tornado and straight line winds?

Tornados involve rotating winds within a thunderstorm. Straight-line wind is a term used by meteorologists to describe any wind within a thunderstorm that is non-rotating.

National Weather Service, Northern Indiana Forecast Office has a great explanation about the difference between the two

Other Types of Damaging Winds