Need trigger to detect Tornado Spin

In my map, I have tornados (based on naga sea witch ultimate) that wander the map, and when a unit comes nearby, it gets thrown in the air. The tricky part is, I want units to have vision as if they were in the air as well as an 1800 vision radius while they are thrown. Up until now, I have been using a hidious trigger that checks every 1 second for the tornado spin buff, and if thats the case, it creates a hidden unit with the visibility and a 1 second expiration timer. So, I'm looking for a more efficient way to do what I need. I tried several events/conditions in test maps, but I can't figure out which event or conditions to use. Any help is appriciated, and I will try to clarify anything you don't understand. Thanks for your time.

Unless some trigger event happens when a unit is thrown into the air, the only way to detect it is with a periodic triger. However, more efficient than creating the dummy sight units every one second would be to just: a) create the unit only once and give it an expiration timer equal to the duration of the buff, and mark the unit with a change in custom value that it already had the sight unit created for it, or, b) try adding and removing the item sight range bonus ability.

I don't see how just 1 dummy unit is going to be significantly more efficient than 1 per second. And I'm already using item sight bonus, so that's out. Thanks for the help though.

you could trigger the casting of cyclone?

You mean trigger for when a unit comes into range of the tornado, cast cyclone on the unit? I guess that might work, but seems like it's a frivilous tirgger. If all else fails, I'll keep it in mind.