Conversations or long sentences were not communicated by smoke.
The smoke signal was created by putting damp grass on a fire. (Legend also has it that blankets were used, but this seems to be a myth created by Hollywood, rather than the truth). The damp grass would cause a column of smoke to rise. The grass could then be taken off and then a minute or so later, another bundle of grass could be placed on the fire. Two columns were usually all that was needed.
Reputedly the location of the smoke also conveyed a meaning, so if it came from half way up the hill, that could signify all was well, but from the top of the hill it would signify danger. Each tribe had their own signalling system and understanding. But they did not have conversations about the weather using smoke signals !