This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
嵕 combines 山 (mountain) with 㚇, but the exact historical development and original meaning are uncertain.
The left side is a mountain 山, and the right side is a complex shape 㚇. Without a clear meaning, picture a mysterious mountain peak with an unusual formation.
For ソウ, imagine the sound of wind blowing over a mountain pass: soh -> ソウ, echoing across the unknown peak.