The protracted La Niña conditions, which began in September 2020, with a short break in 2021 boreal summer, are still continuing in the equatorial Pacific Ocean. WMO Global Producing Centres of Long-Range Forecasts predict the continuation of the current La Niña into the boreal winter of 2022/2023, with a 75% chance in December-February 2022/2023, and 60% in January-March 2023. Thereafter, transition of the current La Niña (a cold phase of the El Niño–Southern Oscillation or "ENSO") to ENSO-neutral conditions is favored in February-April 2023 with a 55% chance, and increasing to about 70% during March-May. The chance of El Niño developing is negligible during boreal winter 2022/2023, slightly increasing after, but still with low chance, around 25% towards the end of the forecast period (May-July 2023). National Meteorological and Hydrological Services (NMHSs) will closely monitor changes in the state of ENSO over the coming months and provide updated outlooks, as needed.
The protracted La Niña conditions, which began in September 2020, with a short break in June-August 2021 are still continuing in the equatorial Pacific Ocean as of mid-November 2022. The sea surface temperature anomalies in the central and eastern equatorial Pacific ranged from -0.9 to -1.4 degrees Celsius (for the week centered on 09 November 2022), with below-average subsurface temperatures in the eastern and east-central Pacific sustaining the cooler sea surface temperatures. The overlying atmospheric conditions, including surface and upper-level winds and patterns of cloudiness and rainfall, remain consistent with La Niña. The Southern Oscillation Index (SOI: defined by the standardized Tahiti minus Darwin sea-level pressure difference), which had shown a significant increase in September, now has a downward trend. Anomalously dry conditions have been observed in the central Pacific (west of the International Date Line), with enhanced convection and precipitation over Indonesia and the western Pacific. On the whole, observed oceanic and atmospheric conditions indicate a continuation of the current La Niña event.
Using the recent observations as the starting point for their dynamical seasonal prediction systems, the WMO Global Producing Centres of Long-Range Forecasts routinely issue global-scale climate forecasts for the coming months. Their latest forecasts and expert assessment indicate that there is a moderate probability for the sea surface temperature anomalies in the central and eastern equatorial Pacific to remain colder than normal during next two overlapping seasons (December-February and January-March). The likelihood of a continuation of the current La Niña is forecasted to be about 75% for December-February 2022/2023, but to decrease to about 60% during January-March, and to 40% in February-April 2023. Termination of the multi-year La Niña, leading to ENSO-neutral conditions, is favored during February-April with a 55% chance. The probability increases to 70% during March-May. The chance of El Niño developing is negligible until later in boreal spring, increasing to around 25% by the end of the forecast period in May-July 2023.
With the current La Niña event entering its third consecutive year and predicted to continue until early 2023, this marks the first “triple-dip” La Niña event of the 21st century, which potentially has serious implications for protracted drought or flood conditions in the impacted regions. Concurrently, the Interdecadal Pacific Oscillation has been strongly in its negative phase since 2017 and strongly negative since 2020, which reinforces the La Niña phase of ENSO. However, it is important to note that El Niño and La Niña are not the only factors that drive global and regional climate patterns, and further that the magnitudes of ENSO indicators do not directly correspond to the magnitudes of their effects. At the regional level, seasonal outlooks need to assess the relative effects of both the ENSO state and other locally relevant climate drivers. Regionally and locally applicable information is made available via regional and national seasonal climate outlooks, such as those produced by WMO Regional Climate Centres (RCCs), Regional Climate Outlook Forums (RCOFs) and National Meteorological and Hydrological Services (NMHSs).
