A churning storm cloud forms, centered on a point you can see and spreading to a radius of 360'. Lightning flashes in the area, thunder booms, and strong winds roar. Each creature under the cloud must make a Con saving throw. On a failed save, a creature takes 2d6 thunder damage and becomes deafened for 5 min.

Each round you maintain concentration produces:
Round 2 Acidic rain falls from the cloud. Each creature and object under the cloud takes 1d6 acid dmg.
Round 3. 6 bolts of lightning strike 6 creatures or objects of your choice beneath the cloud (1 bolt per creature). A struck creature must make a Dex saving throw, taking 10d6 lightning dmg if failed, or 1/2 dmg if successful.
Round 4. Hailstones rain down. Each creature under the cloud takes 2d6 bludgeoning dmg.
Round 5-10. Gusts and freezing rain assail the area under the cloud. The area becomes difficult terrain and is heavily obscured. Each creature takes 1d6 cold dmg. Ranged weapon attacks are impossible. The wind and rain count as a severe distraction, and break spell concentration. Finally, gusts of strong wind automatically disperse fog, mists, and similar phenomena in the area, whether mundane or magical.