What La Niña means for Nome

By Rick Thoman
Alaska Climate Specialist
Alaska Center for Climate Assessment and Preparedness
International Arctic Research Center/University of Alaska
Fairbanks

NOAA’s Climate Prediction Center has issued a La Niña advisory, meaning that the ocean along and near the equator to the south and southeast of Hawai’i are significantly warmer than normal and trade winds are stronger than normal and that these conditions are expected to persist for several months.
La Niña, and its counterpart El Niño, are usually significant factors in the northern hemisphere cold season weather pattern, but especially around the Pacific and in North America (these are not so important for Europe).
So, what does this mean for Nome?
This week’s Climate Watch graphic shows how the early winter (November through January) average temperature (top) and total precipitation (bottom) relative to normal have worked out in each of the 16 La Niñas in the past 50 years.
A glance at the temperatures shows that there is no pattern at all. Early winters during La Niña have been much warmer than normal, like 1984-85, 2001-01 and 2017-18, and much colder than normal, especially 1999-2000 and 2011-12 and some that have been close to normal, like 1995-96 and 2007-08. In other words, La Niña gives us no clue what early water temperatures will be like overall.
It’s a different story with precipitation. Only three of the 16 La Niña early winters have been significantly drier than normal, while half have been significantly drier than normal. So not taking into account things like current sea surface temperatures or sea ice extent, a November through January climate outlook based on only La Niñas since 1975 would favor above normal precipitation but neither above or below normal temperatures.