ENSO Blog

La Niña continues in the tropical Pacific, with both the ocean and atmosphere clearly reflecting La Niña conditions. The current forecast favors the continuation of La Niña through the summer (59% chance), with a slightly lower chance into the fall (50-55% chance). A third-year La Niña would be pretty unusual—we’ve only seen two others since 1950. I’ll run the numbers to see how current conditions add up and what’s factoring into the odds for La Niña later this year. Paint by numbers Let’s take stock of current ENSO conditions (ENSO=El Niño/Southern Oscillation, the whole ocean-atmosphere El Niño/La Niña system) in the tropical Pacific. In March, the sea surface temperature in the key …   Read article

Some would call it the most famous annual March tradition. No, I’m not talking about March Madness, or St. Patrick’s Day. I’m talking about our annual look back at the Climate Prediction Center’s Winter Outlook to see how well it did. Warning: Some math will follow. At the ENSO Blog, we’re not the types to simply give you a thumbs up or thumbs down on how well the outlook performed. That leaves us vulnerable to the whims of our human biases. Instead, we slam some cold, hard statistical math facts on the proverbial table for our readers. If you’d like a refresher, there are seven different verification posts at the ENSO Blog that I’ve written that I highly recommend you peruse. A remind…   Read article

Three-bean salads are a blend of sweet-sour tastiness, implying all good things come in threes. Well, depending on your opinion of La Niña, maybe not all good things, as La Niña—the cool phase of the El Niño-Southern Oscillation climate pattern—reasserted itself in the tropical Pacific this past month with some of the strongest atmosphere-ocean coupling of our double-dip La Niñas so far (winters of 2020-21 and 2021-22). La Niña is now favored to continue into the Northern Hemisphere summer 2022, with nearly equal chances of ENSO-neutral or La Niña thereafter. Is a La Niña three-peat in the offing?  Three-dimensional Back up, La Niña strengthened in February? It did, despite the fa…   Read article

Guest co-author Dr. Kai-Chih Tseng is a postdoctoral research scientist at Princeton University and the NOAA Geophysical Fluid Dynamics Laboratory who is an expert on climate variability and prediction, including the study of atmospheric rivers. In the summer of 2022, Dr. Tseng will begin an assistant professor position in the Department of Atmospheric Science at National Taiwan University. This past December, a mind-boggling 18 feet of snowfall fell in the California Sierra Nevada Mountains! How does so much snow fall in one place in such a short period of time? One of the primary phenomena responsible for such extreme rain and snowfall, particularly in regions like the western U.S., is…   Read article

La Niña is likely to hang around through the spring, with a transition to neutral favored for the May–July period. Hop in, and we’ll cruise through some updates on current conditions and the recent past! On the road again The November–January average Oceanic Niño Index, that is, the three-month-average sea surface temperature anomaly in the Niño-3.4 region of the tropical Pacific, was -1.0 °C. Anomaly means the difference from the long-term average; long-term is currently 1991–2020. This marks our fifth three-month period in a row with an Oceanic Niño Index that exceeds the La Niña threshold of -0.5 °C. Passing this mile marker means this La Niña has persisted long enough to be awarded…   Read article