Visualisation of the sea surface height anomaly in June 2023. Red and orange shades indicate high sea surface heights relative to the reference state, while blue and green shades indicate sea surface heights lower than the reference state. Neutral conditions appear yellow. An above-average sea surface temperature in the central and eastern Pacific is one of the indicators of El Nino conditions, which is the warm phase of a major climate pattern called the El Nino Southern Oscillation (ENSO). The warmer water associated with El Nino causes an increase in sea surface height due to thermal expansion, which displaces colder water in the upper layer of the ocean. On 14 September 2023 the NOAA Climate Prediction Center stated that El Nino is expected to continue through the Northern Hemisphere winter, with a greater than 95 percent chance from January to March 2024. Visualisation created using sea surface height anomaly data available from the Copernicus Marine Service.