JMA Calls La Nina For Central Pacific, US And Australia Reserving Judgement

[hatrack]

According to the Japanese Meteorological Agency (JMA), La Niña has in fact arrived. The Australian Bureau of Meteorology, another of the big tropical Pacific watchers, still has a La Niña watch in place, but is still waiting for its “official” arrival. But the National Oceanic and Atmospheric Administration dropped its La Niña watch last week, indicating that it’s unlikely that a La Niña will form this fall or winter.

All three agencies are looking at the same ocean, but have come to different conclusions about when — or even if — La Niña is going to happen. The main reason comes down to how you define La Niña.

or the average person, it just means cooler-than-normal ocean temperatures. But scientists are a little more precise than that. Let’s start with NOAA and why they’re feeling bearish on La Niña.

“We dropped our watch mainly because of the lack of model support for an extended duration of La Nina conditions that we need to see,” Michelle L’Heureux, a scientist at NOAA’s Climate Prediction Center, said. For NOAA to officially declare a La Niña, ocean temperatures in a specific region of the tropical Pacific (dubbed NINO3.4 for the hardcore nerds out there) need to be 0.9°F (0.5°C) below normal for five running 3-month averages in a row (so September-November, October-December and so on).

EDIT

http://www.climatecentral.org/news/la-nina-forecast-winter-2016-20706

[Gman]

1. The CPC puts out monthly summaries

It was in the September update that they went to EMSO neutral for northern hemisphere fall and winter. Here the latest.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_disc_sep2016/ensodisc.shtml