A tornado is a funnel-shaped cloud that can quickly spit out large amounts of debris. These debris can hurt, damage, and even kill a person, especially if the person is inside the cloud or a nearby building.
It can happen at any time, and often happens during a hurricane or severe thunderstorm. If you know how to spot a tornado on radar, you can take steps to avoid the danger and get out of the way if it does hit.
The red and green colors in a tornado radar image indicate the direction of winds. Red shows winds that are moving away from the radar, and green shows winds that are moving toward the radar.
When a couplet of these winds is next to each other, it indicates strong rotation in the storm.
If the couplet is large and relatively weak, it suggests broad rotation within a thunderstorm that needs to be watched but may not show a tornado on the ground.
This is usually not the case with a tornado that has formed in a supercell.
Another signature of a tornado on radar is a hook echo, which is seen when there's a swirling pattern that looks like a spiral turning clockwise with the "thickness" of the precipitation increasing (or a hook shape). A storm that has this radar signature will usually produce a tornado in that area.
