Tornado activity is monitored by the

Tornado activity is monitored mostly by the
Storm Prediction Center and the National Climatic Data Center.

Hope that helps!

In the United States, tornado activity is monitored by the Storm Prediction Center as well as the National Climatic Data Center (NCDC). Both of these weather centers are branches of the National Oceanic and Atmospheric Administration (NAOO).

Each of these branches watch the weather and wind patterns and make predictions of storms, tornadoes, and hurricanes based off of their information.

Thank you for your question! I hope this helped! Have an amazing day and feel free to let me know if you need any further help! :D