I full time RV and this is on all the time.
It is another layer of protection in addition to TV, phone and radio alerts. It has proven to detect tornado activity two times within 30 miles within the current year.
It is NOT a lighting "Strike" detector.
It detects cloud to cloud lighting intensity over specified periods of time to determine the likelihood of a tornado. Its track record of 95% accuracy is based on 10 yrs of study of the conditions required for a tornado and the results of unit testing.
Understand, the announcement of a "tornado on the ground" will only be released when there is a human observation of it. At Night?
That might be too late. Weather ADVISORIES cover broad areas and are based on wind and cloud formations observed by satellite and weather balloon results.
This tool is designed to be more specific to your locale and to better identify the conditions during an active tornado or just prior to forming a tornado.
In my experience it has gone off 10 minutes before the phone or TV does.
Here's how I use it.
It is on all the time and located next to a window, required for best performance, away from anything that produces radio waves or static from sparks, like an electric motor. You need to set it up on a clear day when there is no activity, NOT during a storm.
Obviously you'll know if it's stormy outside.
There are 5 levels of warnings.
The first 3 are text only displayed on device.
The first AUDIBLE alarm is level 4 when the storm is bad enough that conditions are right for possible tornado formation. I'm now alerted to start thinking about actions I may need to take. At this stage I silence the alarm as I am now aware. Phones, TV's and radios will begin going off soon as well.
The next level alarm is 5 and is also audible plus adds a strobe light. Even if you silence alarm 4, 5 will still sound. Something is happening within 30 miles of you. At this point I start looking for visuals of an actual tornado, heavy lighting at night in a specific direction. Now is the time to take cover or at least be ready to go there at a moments notice.
As stated at the top, this just is another tool to help you make an informed decision.
It is NOT the be all end all solution.
Below is the search text that will direct to the owner's manual of this great tool.
tornado alert owners manual pdf
Be safe out there.