Thunderstorm

Duration: 1 hour, Concentration
You touch a willing creature and it becomes
surrounded by a roiling storm cloud 30 feet in
diameter, erupting with thunder and lightning.
The creature gains a fly speed of 60 feet. The
cloud is transparent to the creature the spell was
cast on, but is heavily obscured to everyone else.
Each other creature that enters or starts it's turn
in the cloud makes a Dexterity saving throw. A
creature takes 2d4 thunder damage on a failure.