El Niño Southern Oscillation (ENSO)
ENSO Response Comparison Plots
Composite (average) atmospheric variables associated with 9 El Niño and 9 La Niña events from 1948 to the present. Events are defined for winter(Nov-Mar) and summer (May-Sep). Anomalies are defined as the difference from the 1981-2010 means (1971-2000 for the climate division data). Options are available for comparing El Niño to La Niña, anomalies to means and winter to summer. Set your browser window as wide as possible to view plots side-by-side.
The composites are based on historic events and should not be construed to represent a seasonal mean forecast. Events vary in their impacts, as the strength, geographic extent, and seasonality of particular events vary. There are different time scales that may act differently. Finally, other climate and weather processes and "noise" may make the impacts of one event different than another. Some events may be associated with very extreme climate conditions which may dominate the composites. Users can explore some of these issues with the links below. The current NOAA official seasonal forecast is available from NOAA/CPC. They also make available an ENSO diagnostic discussion.