NOAA’s Climate Prediction Center has forecasted a third year of La Nina conditions in the Pacific. This is just the third time since 1950 that there has been La Nina three years in a row. There have been no La Nina events since 1950 that have persisted for four years in a row. The existing La Nina event is expected to persist into spring of 2023. Similar to the 2021-2022 wet season, the consensus of climate models is forecasting large scale wetter than average conditions over the Hawai'ian Islands region through April 2023. The distribution of the rainfall may be influenced by the strength of the La Nina. Stronger La Nina events can have a higher than normal trade wind frequency, which will tend to focus rainfall along the east-facing windward slopes. Weaker La Nina events have more weather systems that produce significant leeward rainfall. Early indications are that the current La Nina may be in the weak to moderate range.
La Nina is a natural ocean-atmospheric phenomenon marked by cooler-than-average sea surface temperatures across the central and eastern Pacific Ocean near the equator, and the opposite of El Nino, which features warmer-than-average sea surface temperatures in that region.
Senior Service Hydrologist
NOAA – Honolulu Weather Forecast Office
National Weather Service for Honolulu: https://www.weather.gov/hfo/