Blogs

After a year of dominance, El Niño released its hold on the tropical Pacific in May 2024, according to NOAA’s latest update. El Niño—the warm phase of the El Niño-Southern Oscillation (ENSO), our planet’s single largest natural source of year-to-year variations in seasonal climate—has been disrupting climate in the tropics and beyond since May 2023, likely contributing to many months of record-high global ocean temperatures, extreme heat stress to coral reefs, drought in the Amazon and Central America, opposing wet and dry precipitation extremes in Africa, low ice cover on the Great Lakes, and record-setting atmospheric rivers on the U.S. West Coast.  (That’s an incomplete list! I’d …   Read article

It’s hard to believe that ten years ago a ragtag group of El Niño-Southern Oscillation (ENSO) scientists teamed up with an impossibly patient and wise editor and data visualization team at Climate.gov to start this blog. And it’s even harder to fathom how popular the ENSO Blog has become; we've had 6.6 million lifetime page views and nearly half a million readers in the past year alone. So, thank you to all of our readers who have stuck with us as we delved into some amazingly complex and nerdy topics (and some amazingly awful puns) over the years. And what better way to celebrate ten years than to shamelessly steal a time-honored tradition in the TV sitcom world, the clip show! But inste…   Read article

El Niño weakened substantially over the past month, and we think a transition to neutral conditions is imminent. There’s a 69% chance that La Niña will develop by July–September (and nearly 50-50 odds by June-August). Let’s kick off the ENSO Blog’s tin anniversary with our 121st ENSO outlook update! Attention! First things first: our beloved editor, Rebecca Lindsey, has trained us all very well, including being sure to acquaint our newer readers with the fundamentals of the El Niño/Southern Oscillation climate pattern, or ENSO. ENSO has two opposite phases, La Niña and El Niño, which change the ocean and atmospheric circulation in the tropics. Those changes start in the Pacific Ocean a…   Read article

As polar vortex season winds down, so does Season 1 of the Polar Vortex Blog. In our final post of the season, we discuss whether the season is ending on a cliffhanger or just tying up loose ends. Season finale of the polar vortex The polar stratospheric west-to-east winds have been steadily weakening and as of April 28, the winds at 60 degrees North, 10-hPa reversed direction, becoming east-to-west. As mentioned in the previous post, this breakdown of the polar vortex isn’t a shocking cliffhanger, but rather the final stratospheric warming that occurs every spring as a result of the sun “rising” over the North Pole. Probably the most noteworthy part of the final warming is that it ha…   Read article

Based on some questions from readers and from some stories we’ve seen online in the past month, we’ve come to realize that there may be some confusion about what our experts mean when they talk about there being a “reversal” of the polar vortex. Since my primary role on the blog is to notice when such confusion might happen and try to prevent it, I volunteered to do this unplanned post as penance for having failed to recognize that some of our previous explanations might not have been totally clear. So, let me explain why we are going to stop saying 'polar vortex reversal.' It’s a reversal  In previous posts, Amy and Laura explained that we can estimate the strength of the pola…   Read article