I’ve long seen tornadoes in my dreams and used them as lucid dream triggers. They usually work well as triggers as my dream self easily recognizes that I’ve never before seen them in waking life.
I’ve noticed that these tornado dreams seem to precede severe weather events, usually ones threatening enough to spawn tornadoes. Now I wonder if the tornadoes I see in my dreams may be a mental weather forecast rather than a simple sign I’m dreaming!