Forecasters are predicting with La Niña potentially emerging for the second year in a row it could mean above average precipitation and below-average temperatures in the northern United States this winter.

The National Weather Service’s Climate Prediction Center released its U.S. Winter Outlook Thursday noting that the potential for a La Niña winter is the “biggest wildcard” for how the winter will shape up. La Niña, a natural cooling of the equatorial Pacific impacts weather worldwide, has a 55 percent to 65 percent chance of developing before winter sets in, according to NOAA.

“If La Niña conditions develop, we predict it will be weak and potentially short-lived, but it could still shape the character of the upcoming winter,” said Mike Halpert, deputy director of NOAA’s Climate Prediction Center. “Typical La Niña patterns during winter include above average precipitation and colder than average temperatures along the Northern Tier of the U.S. and below normal precipitation and drier conditions across the South.”

For December through February 2018, wetter-than-average conditions are favored across most of the northern United States, extending from the northern Rockies to the eastern Great Lakes, the Ohio Valley, in Hawaii and portions of Alaska. Conditions across the southern U.S. are expected to be drier than normal.

Below-average temperatures are favored in the Pacific Northwest and the Northern Tier of the country.

NOAA’s seasonal outlooks give the likelihood that temperature and precipitation will be above-, near, or below-average, and also how drought is expected to change, but do not project seasonal snowfall accumulations. Snow forecasts are generally not predictable more than a week in advance because they depend upon the strength and track of winter storms, according to NOAA.