Shockwave LTM in Fortnite arrived on Thursday. "Operation Snowdown will bring in a rotating selection of returning LTMS, including the new Shockwave LTM which is all about knocking your enemies into a powered up Storm, and the debut of Pickaxe Frenzy in LTM form", says Epic Games.
Shockwave LTM Fortnite: Everything You Need to Know
Sadly there is an issue with players losing their Bars when playing the Snowdown LTM and the team said they will provide an update when they have more info. This means playing anything in the Snowdown shuffle, including the Shockwave LTM could result in a player losing all their bars, be careful.
The game mode itself takes place in three rounds in a knockback focused arena. Weapons don't damage players but do knock them back. The more the player is hit, the more they are knocked back. The first team to survival the three rounds gets the Victory Royale.
First, you will drop into the storm circle in a drop pod and evade the storm. Then with each hit of a weapon, players will be knocked back, with each hit making them fly further away. Knocking a player will eliminate them, surviving three rounds will secure the player a Victory Royale.