ENSO Blog

Ocean and atmospheric conditions tell us that La Niña—the cool phase of the El Niño-Southern Oscillation (ENSO) climate pattern—currently reigns in the tropical Pacific. It’s looking very likely that the long-predicted third consecutive La Niña winter will happen, with a 91% chance of La Niña through September–November and an 80% chance through the early winter (November–January). 91%! That’s very high. Why so confident? The first reason is that La Niña is already clearly in force in the tropical Pacific. The August sea surface temperature in the Niño-3.4 region, our primary location for ENSO monitoring, was about 1.0 °C (1.8 °F) cooler than the long-term average, according to ERSSTv5,…   Read article

It’s been a scorching summer in much of the US, but no state has sizzled more than Texas. Does this summer’s unusually persistent La Niña bear some of the responsibility for the extreme heat? In this blog post, we’ll try to figure that out! ENSO impacts on summer US climate: concurrent versus delayed Back in May of 2015, when the ENSO Blog was still in diapers, Tony Barnston wrote about the expected impacts of El Niño on the US summer climate. Tony’s message about El Niño also holds for La Niña: the summer impacts of La Niña are mostly weak or insignificant in the US. Like El Niño, the impacts of La Niña are stronger in the hemisphere experiencing winter. One of the main rea…   Read article

La Niña continues! It’s likely that the La Niña three-peat will happen: the chance that the current La Niña will last through early winter is over 70%. If it happens, this will be only the third time with three La Niña winters in a row in our 73-year record. ENSO (El Niño/Southern Oscillation, the whole La Niña and El Niño system) has the greatest influence on weather and climate during the Northern Hemisphere cold season, so forecasters pay especially close attention when it looks like ENSO will be active in the winter. Hopelessly Devoted to You La Niña is present when the sea surface temperature in the east-central Pacific Ocean is at least 0.5 °C (0.9 °F) cooler than the long-term a…   Read article

When we discuss the El Niño-Southern Oscillation (“ENSO” for short) at the blog, we often take a rather human or physics-y view of the climate phenomenon. We've published loads of articles discussing the mechanics for how ENSO works in the atmosphere and the ocean, and how ENSO impacts humans from droughts and wildfires to floods. (Seriously, check out this index page covering all the ENSO blog posts to date.) But there is more to ENSO than physics and humans! Blasphemy, I know. Because, from the very beginning, ENSO has been a tale about marine life impacts. You simply cannot tell the story of El Niño, for instance, without mentioning its impacts on the anchovy fishery off the coast of P…   Read article

I’m in San Diego this week, gazing out across the Pacific toward La Niña’s cool tropical ocean surface. (I’m not here for Comic-Con, but there are a lot of posters around the city that keep that upcoming event in the forefront.) Just over my horizon, La Niña—the cool phase of the El Niño-Southern Oscillation (“ENSO” for short)—remains in force, despite some warming in the sea surface temperature over the past month or so. Forecasters expect La Niña to continue through the summer and into the fall and early winter. Ka-Pow! Numbers-wise, there’s about a 60% chance of La Niña through the summer, ticking up a bit to the mid 60%s around 66% by October–December 2022. The second most like…   Read article