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.
According to the Quad City Metro area outdoor warning system guidelines, sirens go off for tornadoes, thunderstorms accompanied by winds of 70 mph or higher, or hail that is golf ball sized or larger. All alerts will be sounded by city or county officials when they receive word that severe weather is approaching.