No Niña just yet, but pay attention

Don’t panic just yet, but it’s worth paying attention to a couple of signs out of the monitoring and forecast community that La Niña (the cool equatorial Pacific that tends toward dry winters here in New Mexico) may be about to sneak in the back door. The latest CPC forecast, out Thursday, said as much:

ENSO-neutral or weak La Niña conditions are likely during the next 6-9 months.

Klaus Wolter’s MEI index, which brings together a number of different measures of ENSO activity, just slipped into the negative (La Niña) phase for the first time in more than a year. One month there does not a La Niña make, but it’s worth watching.

And the Pacific Decadal Oscillation index has also gone negative. I’ve been strongly cautioned against reading too much into the month-by-month PDO numbers, because they’re much more useful as a measure of decadal-scale oscillations (remember their name). But again, worth watching.