A burst of bad weather that zaps any runners passing through it, removing an item.
— In-game description, Sonic Forces: Speed Battle
The Storm Cloud is a Trap Item that appears in Sonic Forces: Speed Battle. When used, it will place gray thunderclouds emitting lightning that can block the opponents' way.
The Storm Clouds take the form of gray thunderclouds constantly emitting purple lightning.
In gameplay, the Storm Cloud can only be obtained at random from Item Boxes by Shadow. As with all other Items, Metal Sonic can also use the Storm Cloud if he uses the Steal Item to steal it from the aforementioned user.
When used, thunderclouds will be dropped some distance ahead of the user's current location on all lanes that the user is not currently on. Touching the lightning emitted by the clouds with a playable character (including the user) will cause them to get zapped by an electric attack, which destroys a random object from their inventory and slows them down (the length of the latter effect depending on the level of the Storm Clouds).
To avoid them, the player can run in between them. Unlike the other Trap Item in the game, however, it is not possible for the player to dodge the Storm Cloud by jumping through them. They instead must slide underneath them instead. The Zap effect of the Storm Cloud can be upgraded for each individual user by levelling them to levels 4, 10 and 16.