Tricky rain

So, the other day i was walking to the big shopping center behind the train station. I needed to go there to apply for Carreira Pedestre Popular de Santiago. So I spend more then one hour walking (with no rain what so ever) to the shoping center and back. It is cloudy but really hot, so i carry my jacket in my hand. Sol sends me sms to buy water on the way back, but i decide to first stop by the flat to leave the heavy jacket and unnecessary umbrella. As I head for the store, I feel some drops but it's nothing so I continue. I finish shopping and as I leave the store, I see the rain of biblical proportions. It rains so hard, that there are rivers formed in the streets. So I stand on the door of the store, with no umbrella and no jacket and I waited for the rain to stop for close to half an hour.
The point is: always expect rain in Santiago...