With La Niña officially coming to an end, regions along the southern corridor of the US could see some relief from drought, but ENSO-neutral conditions could also have an effect on enhancing the Atlantic hurricane season.
La Niña Over, Precipitation Could Ease Drought
The NOAA has called an official end to La Niña, saying that ENSO-neutral conditions are likely to continue through the Northern Hemisphere during summer according to the Climate Prediction Center (CPC) final advisory in May 2021.
ENSO is an acronym for El Niño-Southern Oscillation. It refers to a climate phenomenon in which a recurring climate pattern changes global atmospheric circulation, which in turn, has an influence on temperature and precipitation across the globe, according to the National Weather Service (NWS).
During a La Niña, there is a cooling of the ocean surface in the central and eastern tropical Pacific Ocean. For the southern US, a La Niña means below normal precipitation. The southern corridor of the US has been suffering from drought. It’s been so dry, body wash cream for dry skin has been flying off the shelves.
A La Niña causes a variable Pacific jetstream, which pushes north, leaving abnormally or excessively dry conditions for southern latitudes across the US. This typically affects southern California, southern Nevada, Arizona, New Mexico, southern Colorado, Texas, southern Oklahoma, as well as the southern regions of Louisiana, Mississippi, Alabama, Georgia, and all of Florida.
How ENSO-Neutral Can Help Drought
ENSO-neutral means either an El Niño or La Niña and that these conditions are close to average.
Therefore, an end of La Niña bringing ENSO-neutral conditions means that the southern US could see precipitation at average levels, which could provide relief to areas that have been drought-stricken. Unfortunately, there’s a catch.
The NOAA said “neutral conditions are likely to remain through the summer.”
“ENSO has a strong relationship with the Atlantic hurricane season (June–November),” the NOAA said. “[With] La Niña tending to enhance the season.”
In other words, hurricane season might be worse than we thought this year because of the ongoing weather pattern.
A Second La Niña Coming?
The NOAA wrote that “many of the computer models are suggesting that we may see a second-year La Niña, a common occurrence in the historical record.”
“However, the spring predictability barrier—forecasts made in the spring tend to be less skillful than forecasts made in other times of the year,” the NOAA added, “reducing the confidence in forecasts for the fall and winter.