|El NiĆ±o-Southern Oscillation
The most common way of monitoring the El NiĆ±o-Southern Oscillation phase is by looking at sea surface temperatures in the equatorial Pacific Ocean. The animated map below shows sea surface temperature anomalies over the past three months. Warm/positive anomalies are associated with the El NiĆ±o phase, while cool/negative anomalies are associated with the La NiĆ±a phase.
Several climate models also provide ENSO forecasts, again based on sea surface temperatures over a specific region in the equatorial Pacific Ocean. The graph below shows the observed ENSO phase for the previous three-month period (as a black circle near the left side of the image), along with computer model forecasts for the next 12 months. The thick yellow line represents the average forecast of all dynamical models.
In North Carolina, a warm/positive phase (El NiĆ±o) event is often associated with cooler, wetter conditions and an increased chance of winter weather. Likewise, a cool/negative phase (La NiĆ±a) event often brings North Carolina warmer and drier conditions. The impacts of ENSO on North Carolina are most prominent during the winter.
Because ENSO conditions are generally slow to change, with a frequency on the order of months to seasons, we have some skill at issuing forecasts on a seasonal and even annual basis.
For more information about ENSO, visit our information page or the Climate Prediction Center's page that includes past, current and forecast conditions.