Guest blogger Ken Takahashi assesses the prospects for this El Niño to be an extreme one in the eastern tropical Pacific, like the 1982 and 1997 events were.

ENSO forecasters are predicting this El Niño will be a strong one. What does that mean?

Part science expert, part ringmaster, Jessica Blunden shares the challenges and the value of putting together the State of the Climate report every year.

“El Niño is Strong!” “No, it’s Moderate!” “But the [insert your favorite ENSO indicator here] is the largest it’s been since the El Niño of 1997-98!”

There’s a very high probability that El Niño will continue through the fall and early winter, and it could become a strong event.

Everyone's asking if the arrival of El Niño guarantees that 2015 will set a new record for warmest global temperature. In his latest blog, Deke Arndt explains why it's possible--maybe even likely--but not guaranteed.

El Niño is the 800-pound gorilla for the winter climate in the U.S., but in summer, it's more like a 6-pound Chihuahua.

reason for the spring barrier

Why is it so difficult to make a good ENSO prediction during the Northern Hemisphere spring? 

ENSO is a complicated thing to model. What are the challenges, and how can we overcome them?

El Nino conditions strengthened in March. Where do forecasters think we're going from here?