The Odds of a Third Dry Year?

We’re barely into our second La Niña winter, but some experts are already beginning to think about what it might mean to have a third. The first brought serious drought to New Mexico, Texas and their neighbors. We’re heading into what looks like the second running this winter. Now one of the leading experts on how the climate pattern has played out in the past is laying odds on the chance of a third. From Kate Galbraith at the Texas Tribune:

The main cause of the drought, the most intense in recorded Texas history, is back-to-back episodes of La Niña, a Pacific Ocean phenomenon that almost always brings dry conditions to the state. The bad news is that, based on the historical record, there is a 40 percent chance of La Niña returning for a third consecutive year, according to Klaus Wolter, a research associate with the Earth Research Laboratory at the National Oceanic and Atmospheric Administration (NOAA).

That record consists of 10 instances over the past century in which La Niña has appeared for two years in a row (normally it does not recur). However, Wolter emphasized, 10 episodes is a fairly limited data set. And — here’s the good news — the other six times, an El Niño has followed the two La Niñas, bringing unusually wet weather.