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.
The difference between a tornado watch and a tornado warning means the difference between taking action or taking precautions. A watch means that conditions are favorable for a tornado to occur. A warning means that a tornado has been seen or picked up by radar. A warning requires you to take shelter and brace for a potential tornado.