What’s With The Weather?

Torrential winter rains in normally sunny L.A. and balmy days in the normally frigid Northeast are side effects of a powerful tropical ocean current called El Nino, which periodically disrupts worldwide weather.

How It Works

El Nino is born of a dance between the wind and water; no one is certain what causes it.

1. Every 3 to 7 years, there is an unusual warming of waters in the tropical Pacific.

2. Trade winds weaken.

3. A warm water mass begins moving eastward.

4. Those movements fuel the creation of more rain clouds.

5. The path of the jet stream is redirected, altering storm tracks.

Tracking El Nino

In El Nino years, shown in white, there is a marked relationship between ocean temperature and rainfall.

Damage From the Last Big Hit

The economic toll of the last great El Nino, in 1982-83:

* Flooding

Bolivia: $300 million

Ecuador, northern Peru: $650 million

Cuba: $170 million

U.S. gulf states: $1.3 billion

* Hurricanes

Tahiti: $50 million

Hawaii: $230 million

* Drought / Fires

Southern Africa: $1 billion

Southern India, Sri Lanka: $150 million

Philippines: $450 million

Indonesia: $500 million

Australia: $2.5 billion

Southern Peru, Western Bolivia: $240 million

Mexico, Central America: $600 million

Total: $8.1 billion

Related story, A1 Source: National Oceanic and Atmospheric Administration * Measured along the equator, in Fahrenheit. ** At Christmas Island, in inches.