kinda doubting it will happen cause I think it would be a lot to code, but would be neat if it did.
Currents - both water and wind. move the character. the stronger the current the more forceful the push. May sweep away players, npcs, and/or structures, depending on the strength of the currents.
–Additional possibility with this particular idea is the addition of structures that use currents (such as wind mills or water mills)
Rain in the desert causing flash flooding. - sweep away or submerge structures built in and/or near dried river beds. Include currents
Hail storms - depending on severity/size of stones, may cause damage to players, npcs, and structures.
Tornado - pick up things (players, npcs, mobs, structures, anything not bolted down!) and toss them!
Lightning - to seek out and strike high points… wet objects… metal… etc.