The Enso Cycle

Abnoral WARMING of the Eastern Pacific Ocean

Trade winds reversed so they go West to East

Warm water sloshes EAST so you get dry/drought conditions and high pressure in AUSTRALIA

Humboldt current shuts down and food chain is disrupted

Low pressure and floods in Peru (South America) - warm water rising, cooling and condensing then raining. Up to 10 degree increase in water temp. 

Abormal COOLING of the Eastern pacific oceans

trade winds EAST to WEST are INTENSIFIED

High altitude flow goes West to East and it's cooler

Low pressure over AUSTRALIA and flooding eg Queensland 2010 floods

Severe droughts and HIGH pressure over South America

Humboldt current remains

El Nino:

Less rainfall in southeast Asia, new zealand, australia and india -> crop failure, wildfires etc

Heavy rain in california, mexico, peru and equador

Warmer water off the coast of South America devastates fish catches

La Nina:

Higher rainfall than normal in Indonesia and Philippines

...lower than normal in South America