Hereâs why I chose the NASM certification! Did you need any sort of background related to the field going into the program? Nope, you just need to make sure that you have a current CPR and AED certification before you take the exam. How long does your certification last before you have to renew it?
Tornado Warning. This is issued when a tornado is indicated by the WSR-88D radar or sighted by spotters; therefore, people in the affected area should seek safe shelter immediately. They can be issued without a Tornado Watch being already in effect. They are usually issued for a duration of around 30 minutes.
If a tornado warning is issued, it means that a tornado has actually been spotted, or is strongly indicated on radar, and it is time to go to a safe shelter immediately. Be alert to what is happening outside as well. Here are some of the things that people describe when they tell about a tornado experience: 1  A sickly greenish or greenish black color to the sky. 2  If there is a watch or warning posted, then the fall of hail should be considered as a real danger sign.