Fire from heaven

38 Then the fire of the Lord fell and consumed the burnt offering and the wood and the stones and the dust, and licked up the water that was in the trench (1 Kgs 18:38). 

i) What kind of "fire" fell from heaven? An obvious candidate is lightning. If so, this might well be a case of polemical theology. Baal was a storm god, so when Yahweh backs up his own prophet (Elijah) by raining thunderbolts on the burnt offering, in a showdown with the priest of Baal, that publicly humiliates the reputation of Baal. 

ii) Perhaps, then, we should visualize a storm cloud suddenly, spontaneously forming over the burnt offering. That's all the more striking given the drought.