whirlwind
颴 centers on a spinning, violent wind: a whirlwind. The meaning is specific to this meteorological phenomenon.
颴 combines the wind radical 風 with a phonetic component that likely contributed the sound. The exact historical development of the inner component is uncertain.
The wind enclosure 風 wraps around a spinning inner shape, like a whirlwind trapped inside a container. Picture the wind swirling violently within.
For セン, imagine a whirlwind spinning a thousand (千, せん) leaves in a tight spiral: 千 -> セン, and the wind whirls them around.