WEATHER - We are never completely sure what an El Nino will bring because none of them are exactly the same. However, most of the effects are the same, only with more or less intensity.
When El Nino comes, the easterly trade winds collapse, or even reverse. A weakening in the winds causes a slight change to the surface temperature of the ocean. While this is happening, the change in wind and pressure increases.
Wet weather that is usually in the western Pacific Ocean moves east, and dry weather from the east moves west. This causes heavy rain in South America, it can cause drought in southeastern Asia, India, and southern Africa, plus, it brings unusual weather to large parts of the United States. California, for instance, gets above average precipitation, and many, many storms. This may be because it is thought that El Nino stops the Atlantic hurricane season, but helps the Pacific hurricane season. It produces warm water in the ocean, causing more clouds and thunderstorms than usual over the central Pacific.
El Nino dissrupts temperature and rainfall patterns around the world, giving places warmer or colder temperatures, or more or less rainfall.