The plot for SHARKNADO 3' by Andrew Barr.
It's been three weeks since the events of Sharknado 2. Finn and his now ex-ex-wife April have decided that they no longer want to be in danger of encountering another Sharknado so they move to THE MOON! Mean while on earth, due to global warming, genetic engineering, and organic foods, tornados become sentient. These new sentient tornados make a pact with the sharks of the world to once and for all wipeout the human race.
On board the international space station great strides are made in training dolphins to combat the threat of increasing numbers of sharknados. Unfortunately a Sharknado, disguised as a NASA scientist, has discovered this plan. An elite group of sharknados, headed up by a brash shark typhoon stage an attack on the ISS destroying it and all the the communications satellites communicating with the moon. But one dolphin escapes and heads to the moon to warn Finn and the moon that sharknados have made it off earth and are heading his way. Finn teams up with the dolphin to turn the moon into a giant antisharknado bomb to finally end the Sharknado threat. Will they succeed?
Yes. Yes they do.
But during a post credit sequence we find out the world is about to face a new threat...
Hurricrab is a giant spinning crab. Just one but he's huge.