Radical
Smoke

Mnemonic

A tipi bakes under the sun. Inside, a little fire crackles, and smoke spirals up through the opening at the top. The sun heats the tipi walls until even a little ember fills it with thick smoke, billowing out like a signal cloud.
Additional thoughts
Picture the classic image: a tipi silhouetted against a bright sun, a thin little wisp of smoke rising from its peak. The three components stack visually just like the kanji — tipi on top, sun in the middle, little at the bottom.
Quick recall
A tipi under the sun with a little fire sends smoke skyward.