Obscurement

A bank of fog up to a 20-foot cube in volume billows out from the point the caster designates. The cloud moves at a rate of 10 feet per round under the control of the caster (so long as they concentrate on it). The fog obscures all sight, including Darkvision, beyond 5 feet; beyond that all creatures will be effectively blind. The cloud persists for the entire duration even if the caster ceases to concentrate upon it, but a moderate wind (11+ mph) disperses the fog in 4 rounds and a strong wind (21+ mph) disperses it in 1 round. This spell does not function underwater.