La Nina ends in the central, tropical Pacific Ocean

ANCHORAGE, Alaska (KTUU) - According to the National Oceanic and Atmospheric Administration, water temperatures in the central and eastern Pacific Ocean near the equator have returned to normal. This marks the end of the cooling phase of those waters, known as La Niña, which has been occurring over the past three winters.

Even thousands of miles away, La Niña still impacts Alaska’s weather, mostly during winter months with variable temperatures and precipitation patterns. The main benefit to being under the influence of La Niña, or its more well-known warm phase — El Niño — is that it gives forecasters one of the major indications of what the long-range outlook might be like.

Climate specialist Rick Thoman with the University of Alaska Fairbanks described the effects of La Niña on Alaska’s weather.

“What really gets us for Alaska is we can look to the equatorial pacific as a thumb on the scales for any kind of sustained weather patterns as we go into the spring months,” Thoman said. “As always, whether it’s El Niño, La Niña, or in between, that neutral category — it’s of course just one of the players in the big picture.”

With no strong signal in either direction, however, forecasters will look to smaller-scale features in the atmosphere to determine long range outlooks, features which are highly variable — and thus less predictable — which decrease the confidence in those outlooks.

An extended version of a conversation with Rick Thoman can be found on the Podcast, “In Depth Alaska.” Thomas talks further about La Niña, and touches on the state’s snowpack, as well as a brief look at what can be expected for the upcoming fire season.

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