El Nino is the strongest climate signal in the ocean and atmosphere systems. It is a non-cyclic recurrent event that dramatically changes the weather patterns around the globe, producing floods and in parts of the world and droughts in other parts. El Nino has happened for centuries. Today scientists have very sophisticated tools to monitor and predict El Nino months in advance. When the warm Pacific waters flow from East to West, major rains are in the Indian Ocean and droughts in Peru to Northern California. Scientists can forecast when the warm Pacific wasters reverse and flow East and cause droughts in the Western Pacific and floods in California.