The National Oceanic and Atmospheric Administration (NOAA) released its 2017-18 winter outlook for the United States on October 19. In the video above, Mike Halpert of the Climate Prediction Center – part of the National Weather Service, best known for its United States climate forecasts based on El Niño and La Niña conditions in the tropical Pacific – explains these experts’ projections for temperature, precipitation and drought during the coming winter across the U.S, assuming – as both observations and computer forecasts suggest – La Niña conditions do develop, for the second year in a row.
NOAA called the possibility of another La Niña “the biggest wildcard” in how this year’s winter might shape up. NOAA also pointed out that La Niña has a 55- to 65-percent chance of developing before winter sets in.
Overall, NOAA’s outlook suggests a relatively cooler, wetter winter in the U.S. North and a warmer, drier winter in the U.S. South. It suggests drought is likely to persist in U.S. northern Plains.
In the video, Halpert explains more about what another La Niña would mean, for example, possible greater-than-average snowfall around the Great Lakes and in the northern Rockies, and less-than-average snowfall throughout the mid-Atlantic region.
Other factors that influence winter weather include the Arctic Oscillation, which influences the number of arctic air masses that penetrate into the South and is difficult to predict more than one to two weeks in advance, and the Madden-Julian Oscillation, which can affect the number of heavy rain events along the West Coast.
Watch the video for more details.
Bottom line: Video explanation of NOAA’s winter outlook for 2017-18.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.