Portland, Oregon, is a city right next to northern west coast of the USA. Besides being very close to the sea, it is also laid on a river. The sun that heats up the ocean and the river leads to evaporation, causing water vapour to ascend, because of a few wind currents, this water vapour is taken to Portland's area where it colds down and condensates, raining over Portland.
D. Watershed - a watershed is the area in which runoff, rivers, and streams run into a larger body of water
