Despite the currently pleasant weather, winter is imminent – and the anticipated La Niña in the Pacific could influence the winter outlook for 2024-25.

Mid-November is expected to bring an official announcement regarding the formation of La Niña, during the monthly climate update from federal forecasters, as it will significantly affect winter weather patterns.

Typically, La Niña winters in the U.S. are characterized by cold and snowy conditions in the Northwest, with most Southern states experiencing drier than usual weather, states the Climate Prediction Center. Additionally, the Southeast and mid-Atlantic regions often experience above-normal temperatures during La Niña winters.

The latest forecast from the Climate Prediction Center indicated a 60% probability of La Niña conditions developing by the end of November. Once established, La Niña is expected to persist until January-March 2025 though it is likely to be a mild occurrence.

Understanding La Niña

La Niña is a natural climate phenomenon defined by cooler-than-average sea temperatures in the central and eastern areas of the Pacific Ocean. It is classified as such when the temperature drops at least 0.9 degrees Fahrenheit below average for three consecutive months.

“Although this might appear to be a minor temperature change, it can lead to major shifts in global weather patterns,” noted AccuWeather meteorologist Brian Lada.

La Niña plays a crucial role in influencing weather across the United States, particularly in late fall, winter, and early spring. It contrasts with the better-known El Niño, which occurs when Pacific Ocean temperatures rise by at least 0.9 degrees for the same duration.

Forecasting a mild, dry winter for many in 2024-2025

Federal forecasters recently indicated that due to the expected La Niña event, most regions of the southern U.S. and the East Coast are likely to see warmer than average temperatures this winter. Additionally, the southern half of the country – stretching from southern California to the Carolinas – is predicted to receive less than normal rainfall and snowfall, raising concerns about potential drought conditions.

Jon Gottschalck, head of the Operational Prediction Branch at the Climate Prediction Center, stated, “This winter, we expect the emerging La Niña to shape upcoming weather patterns, especially in terms of precipitation.” However, they also mentioned that a weaker La Niña “means it’s less likely to create typical winter impacts,” as noted by the CPC.

The forecast covers December, January, and February, collectively known as meteorological winter.

Snowfall predictions for the Great Lakes and Northwest

Areas known for heavy snowfall could receive significant amounts of snow this winter, according to CPC’s precipitation forecast. Regions such as the Great Lakes states, the Pacific Northwest, and the northern Rockies are expected to experience wetter-than-average weather.

While the specifics on whether precipitation will occur as rain, ice, or snow are not detailed in the forecast, it is highly probable that much of the precipitation in these colder regions will manifest as snow.

How much snow can be expected? Some of the snowiest places in the U.S. and the world are in the regions likely to receive large snowfalls this winter. For instance, the Mount Baker ski area in Washington state recorded a remarkable 95 feet of snow in the winter of 1988-89.

Moreover, areas downwind of Lake Erie in New York, known for heavy lake-effect snow, can experience “some of the heaviest snowfall globally,” remarked Weather.com meteorologist Jonathan Erdman, who recalled that “in November 2022, parts of the Buffalo region were buried under 81 inches of snow during a multi-day lake-effect snow event.”

‘It will still be cold this winter’

In the Southern U.S., weather experts are reminding people that a forecast predicting a generally dry and mild winter doesn’t mean that cold weather won’t show up.

According to Gary Goggins, a meteorologist from the National Weather Service in Birmingham, Alabama, even with a favorable overall forecast, chilly days and wet spells are still expected this winter.

“This winter will still experience cold temperatures,” he stated. “There will be days, and stretches of time, with significant cold. Weather systems will pass through the state bringing cold spells and potentially severe weather just like we see every winter.”

What about snowstorms and blizzards on the East Coast?

The forecast released last week mainly indicates areas where temperatures and precipitation trends might be above or below the average.

This winter forecast does not provide details on how much of the precipitation will fall as rain, snow, or ice—only that the total amount may vary. Predictions for snowfall heavily depend on the intensity and trajectory of winter storms, which typically can’t be accurately anticipated more than a week in advance, as per the center’s guidance.

However, Gottschalck mentioned that the path of nor’easters on the East Coast might allow for warmer air to reach major Northeastern and Mid-Atlantic cities, potentially leading to more rain instead of snow. Nonetheless, he cautioned that snowstorms are still a possibility, depending on the weather patterns at that time.