Blogs

While I’ve usually written this post in October, this year we decided to wait until a month before winter (December–February) starts. In past years, we’ve asked if El Niño (or La Niña) will play a role in the winter’s outcome. This year is different, however, as ENSO-neutral is present and expected to persist through the winter and into the spring. So what does NOAA’s Climate Prediction Center (CPC) base their winter outlook on when ENSO-neutral is in the cards? Read on to find out. Other clues for seasonal prediction Aside from ENSO, the recent trend in temperature and precipitation turns out to be the most skillful predictor on seasonal time scales. As Tom said in his post on the top…   Read article

ENSO is pretty quiet right now, with neutral conditions firmly in place. Forecasters estimate about a 70% chance that neutral conditions will continue through the winter, and a 60-65% chance through spring. With ENSO snoozing in the back yard, we’ll take a tour of the tropical neighborhood to see who else is out and about. Snuffleupagus Even though our old friend the Niño3.4 index (that is, the departure from the long-term average temperature in the central tropical Pacific) has spent the last few weeks hovering around 0.5°C above average, the overall El Niño/Southern Oscillation (ENSO) system is solidly neutral. To qualify for El Niño conditions, we also require an expe…   Read article

The Pacific Ocean is throwing a bit of a temper tantrum these days, but it’s not where you think it might be. Often we focus on the tropical Pacific Ocean because it’s where ENSO takes center stage, but currently temperature departures across the Tropics are pretty blah. Instead, for the past few months, it’s the North Pacific Ocean that pops out at you—a gigantic red sore that covers much of the eastern basin.   As our colleagues over at NOAA Fisheries explained last month, this feature is a Marine Heatwave. Marine heatwaves are considered prolonged, large-scale warm water events (1). Back in 2014-16, people started calling a very pro…   Read article

There’s about an 85% chance the tropical Pacific will remain ENSO-neutral through the fall, and a 55-60% chance of continued neutral through the spring. We’ll talk about the current conditions and check in on the Atlantic hurricane season. A Nightmare on ENSO Street But wait, you say—Niño3.4 measured 0.5°C above the long-term mean last week! Doesn’t that mean El Niño? While the El Niño threshold is indeed 0.5°C above average, that must persist for several months in a row, and provoke an atmospheric response, to qualify as El Niño conditions. The sea surface temperature in our various ENSO monitoring regions can vary from week to week, a…   Read article

In recent years, a popular debate has been occurring within the climate community. No, it’s not whether climate change is occurring and caused by humans. (It is.) Instead, it’s regarding how much of an effect, if any, the rapid warming of Earth’s frozen cake-topper we call the Arctic, and the corresponding reduction in Arctic sea ice, has been having on winter across the mid-latitudes where most of us live. The debate arose because, while winters have in general warmed during the last century, some regions have shown a weak cooling trend for certain periods. A cooling trend, from around 1990 through 2013 in landmasses across the mid-latitudes, has been noted in previous research (Cohe…   Read article