Giant Storm

Though most storm giants live solitary lives, they do
occasionally pass one another while traveling, gather
together for mating rituals, or convene to divine the
future. When they do so, their presence creates
enormous storms that spiral away from the giants.

A giant storm is an intense thunderstorm that
raises 30- to 60-foot waves over water and dumps
enough rain to flood a square mile of flat ground. The
area within the storm is heavily obscured and difficult
terrain. A creature that starts its turn within the
storm is deafened until the start of its next turn and
must make a DC 13 Dexterity saving throw or take 2d4
lightning damage and be pushed 20 feet in a random
direction by wind. On initiative 20, losing initiative ties, unsecured objects in the area are pushed 20 feet in a
random direction.

A successful DC 18 Intelligence (Nature) check or
Wisdom (Survival) check allows a character to
recognize a giant storm 1 minute before it strikes,
allowing time to seek shelter. A giant storm typically
lasts 2d4 x 8 hours.