Niantic has added a new Legendary Pokemon into their Pokemon Go game and this time, it will be the Legendary Pokemon from Gen 5, Tornadus, one of the three Legendary Pokemon called the Forces of Nature from Unova.
Tornadus will be appearing in Raid battles starting from the 4th of February to the 25th of February. Tornadus is a Flying Type Pokemon which means your best bet would be to go into battle with Rock, Electric and Ice-type Pokemon.
Pokemons like Rhyperion and Raikou would be your best option. Do not go in with a Ground-type Pokemon as Ground-Type attacks are not going to be effective against a Flying Type. Other types like Grass, Bug, and Fighting are also weak against Flying types.
With that, you can start assembling your team and try your luck at catching Tornadus.