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 NOAA states that the current average warning time before a tornado-due to advances in weather technology, such as Doppler radar-is 13 minutes.The residents of Moore, Oklahoma, got 16 minutes lead time, but this may have been due to Oklahoma having more spotters than other areas.he average lead time for a tornado warning in the United States is 14 minutes. However, in recent years lead times have been as long as 39 minutes, while in other â¦ cases there has been no warning.