El Niño and La Niña

CPC - La Niña/El Niño Coverage
Regularly updated discussion and coverage of the La Niña/El Niño weather system including global and regional impacts and forecasting.
http://www.cpc.noaa.gov/products/analysis_monitoring/lanina/

CPC El Niño/Southern Oscillation (ENSO)
Coverage of the weather system from the Climate Prediction Centre, including forecasts, historical info, and the impact of the system on weather patterns.
http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/

El Niño and La Niña: Tracing the Dance of Ocean and Atmosphere
National Academies popular article describes the basic scientific research that led to our current understanding of these weather phenomenon.
http://www7.nationalacademies.org/opus/elnino.html

El Niño/La Niña Watch
Archive of images and news releases about observations of the El Nino/La Nina phenomenon in the Pacific Ocean by the U.S./French TOPEX/Poseidon, Jason-1, and other NASA/JPL satellites and instruments.
http://topex-www.jpl.nasa.gov/elnino/index.html

What is an El Niño?
Illustrated explanation with realtime graphics and animations of data from the tropical Pacific Ocean. From NOAA.
http://www.pmel.noaa.gov/tao/elnino/el-nino-story.html

What is La Niña?
Illustrated explanation with realtime graphics and animations of data. Also numerous links to reference material from NOAA.
http://www.pmel.noaa.gov/tao/elnino/la-nina-story.html