Weather Words: Tornado Debris Signature

As a meteorologist, there’s not much more frightening than seeing a tornado debris signature (TDS) show up on radar. During severe thunderstorms, we look for certain shapes and visual ques to determine if a tornado has formed.

On radar, we can look at something called a correlation coefficient (CC) to spot a TDS. If a TDS shows up on radar, that indicates that the tornado is actually lofting debris into the air. This is incredibly valuable when tracking tornadoes in rural areas where no storm spotters are around, and also at night when physical tornadoes are difficult to see. If we see a TDS on radar, this means there is a tornado causing damage and anyone in the path needs to seek shelter immediately.

Airborne tornado debris consists of items that are vastly different sizes and shapes, falling to the ground much differently than precipitation, which is what the CC parameter detects. As you see from the image above, it's clearly shows up on the imagery.

Regardless of what we see on radar, it's always important to make sure you have a plan in place before severe weather strikes. Know what you and your family would do, and where you would go if a tornado warning is issued. If you don't have a plan, or are unsure of what you should do, here are some tips that can help.

Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.