Will a Weak La Niña Influence Snowfall This Winter?

It has been about one week since La Niña has officially been in place. Now that forecasters are growing more certain that the climate phase will remain a driving factor through February, how will that impact the amount of snow that falls this winter? Read on for more details about the long-range snowfall forecast.

Understanding the Impact of La Niña on Snowfall Expectations

Before we dive into the snowfall predictions for the upcoming season, let's take a look at what La Niña means on a larger scale. La Niña is defined as the periodic cooling of the ocean water temperatures in the eastern and central Pacific near the equator. The phase is officially declared by the Climate Prediction Center (CPC) out of the National Oceanic and Atmospheric Administration (NOAA) when sea-surface temperatures dip to at least 0.9 degrees cooler than average for at least three straight months. La Niña impacts the weather all over North America and beyond

This phase is the opposite of El Niño, a time when the waters trend warmer.  The latest computer models are signaling that this will be a weak La Niña, limiting its overall impact.

Meteorologists are able to look at previous weak La Niña winters for signs pointing to how this year's snowfall accumulations may play out. The CPC examined snowfall amounts during various La Niña winters between the years 1950 and 2009 to determine patterns. What they found was that weaker La Niña's tend to lead to above-average snowfall for the northern U.S., stretching from the Cascades in the Pacific Northwest, through the Upper Midwest, and into New England.

Conversely, snowfall amounts trend lower than average in the southern Rockies and in some areas of the Ohio Valley.

Snowfall Trends in Specific Regions