El Nino could usher in decade of stronger events

El Nino is causing ocean water temperatures to rise across the central and eastern Pacific.

FILE: In Miami, beachgoers are staying indoors during what's already the third-wettest December in local history. Picture: unsplash.com.

NEW YORK - In Buffalo, it hasn't snowed yet this year.

A Duluth, Minnesota, newspaper reported that the temperature was 40 degrees above zero, not below.

And in Miami, beachgoers are staying indoors during what's already the third-wettest December in local history.

What's going on with the weather?

It's the phenomenon called El Nino, which is happening now as ocean water temperatures rise above normal across the central and eastern Pacific, near the equator.

Its effects will leave the US Northeast warmer than usual, the Midwest drier, and the West and the South wetter.

And scientists have a message for everyone bracing for one of the strongest El Nino events on record: get used to it.

While El Nino oscillates on a more or less yearly cycle, another dynamic in Pacific Ocean water temperatures, known as the Pacific Decadal Oscillation (PDO), has the potential to accelerate global warming and increase the severity of El Nino episodes, scientists said. The last time the PDO was, as it may be now, in a prolonged positive, or "warm" phase, it corresponded with two of the strongest El Ninos on record.

Previous warm phases have also coincided with increased precipitation on the US West Coast, signaling potential relief for California from a severe drought.

Before January of 2014, the world experienced a 15-year period of mostly negative values for the Pacific oscillation, according to data maintained by Nathan Mantua, an atmospheric scientist at the National Oceanic and Atmospheric Administration's (NOAA) Joint Institute for the Study of the Atmosphere and Oceans.

That period saw only weak or moderate El Nino events. During the 21 years before that, the Pacific oscillation values trended mostly positive, a period that coincided with the 1982-83 and 1997-98 El Nino events, two of the strongest on record.

Now, scientists are beginning to wonder if the 15-year period of relative El Nino calm is coming to a close, marking the start of a warmer, stormier era akin to the 1980s and 90s.

The PDO index has been positive for 22 months through October, the longest such streak since a 26-month positive period between 2002 and 2004. Scientists are not sure if the current streak marks a longer-term turnaround or just a temporary blip like the 2002-2004 streak.

"It's more likely that we'll have a change in phase and we'll remain in positive territory," said Kevin Trenberth of the National Center for Atmospheric Research in Boulder, Colorado, noting that while a decadal shift was far from a guarantee, the odds in favor are approximately 2-to-1.