Albert Barnes Commentary 1 Kings 18:44

"And it came to pass at the seventh time, that he said, Behold, there ariseth a cloud out of the sea, as small as a man`s hand. And he said, Go up, say unto Ahab, Make ready [thy chariot], and get thee down, that the rain stop thee not." — 1 Kings 18:44 (ASV)

A little cloud ... - Sailors know full well that such a cloud on the far horizon is often the forerunner of a violent storm.