Have you ever wondered why one year we’re so hot, and the next cooler? Or record snow this winter… then bone dry the next?You can partly blame the "El Nino-Southern Oscillation" or "ENSO" for short. It is a shifting global pattern, pairing sea-surface and atmospheric temperatures in the Pacific Ocean.
Fluctuations in these temperatures impact large-scale air movements in the tropics… leading to predictable changes in U.S. weather patterns. ENSO can occur in three stages: El Nino, La Nina or ENSO Neutral. This pattern shifted back and forth every two to seven years.
![](https://media.weathernationtv.com/app/uploads/2021/09/la-nina-el-nino-1.jpeg)
El Nino is characterized by *above* average sea surface temperatures in the Pacific. It is associated with wetter than average conditions along the Gulf of Mexico. In stronger El Nino years, there is a higher probability of heavy precipitation in the southwestern United States.
![](https://media.weathernationtv.com/app/uploads/2021/09/el-nino-pattern.jpeg)
La Nina is the opposite… characterized by *cooling* of the Pacific Ocean surface. La Nina phases tend to favor Atlantic Hurricane development. For example, the record setting 2020 season. In the lower-48, we tend to see cooler and wetter winters in the northern part of the country.
![](https://media.weathernationtv.com/app/uploads/2021/09/la-nina-el-nino-2.jpeg)
When ENSO is neutral, it means the sea surface temperatures are right around average or the atmospheric temperatures and ocean temperatures even themselves out.
![](https://media.weathernationtv.com/app/uploads/2021/09/enso-neutral-pattern.jpeg)
Stay with WeatherNation as we continue to bring you update on what phase of ENSO we are in and your top weather headlines.