Washington, DC – Climate forecasters with the U.S. National Oceanic and Atmospheric Administration (NOAA) are officially back on board with La Niña.
Forecasters at NOAA’s Climate Prediction Center issued their U.S. Winter Outlook on Thursday, saying that La Niña is expected to influence winter conditions this year. After dismissing the idea of a La Niña pattern last month, this month the Climate Prediction Center issued a La Niña watch, predicting the climate phenomenon is likely to develop in late fall or early winter. La Niña favors drier, warmer winters in the southern U.S and wetter, cooler conditions in the northern U.S. If La Niña conditions materialize, however, forecasters still say that it should be weak and potentially short-lived.
“This climate outlook provides the most likely outcome for the upcoming winter season, but it also provides the public with a good reminder that winter is just up ahead and it’s a good time to prepare for typical winter hazards, such as extreme cold and snowstorms,” said Mike Halpert, deputy director, NOAA’s Climate Prediction Center. “Regardless of the outlook, there is always some chance for extreme winter weather, so prepare now for what might come later this winter.”
Video: The U.S. Winter Outlook for 2016-17 from the NOAA Climate Prediction Center
Other factors that often play a role in the winter weather include the Arctic Oscillation, which influences the number of arctic air masses that penetrate into the South and create nor’easters on the East Coast, and the Madden-Julian Oscillation, which can affect the number of heavy rain events in the Pacific Northwest.
For December through February, the core of the U.S. ski season, forecasters say that wetter than normal conditions are most likely in the northern Rockies, around the Great Lakes, and in western Alaska. Drier than normal conditions are most likely across the entire southern U.S. and southern Alaska.
Through those same months, forecasters expect warmer than normal condition across the southern U.S., extending northward through the central Rockies, in western and northern Alaska and in northern New England. Cooler conditions are most likely across the northern tier from Montana to western Michigan.
The rest of the country falls into the “equal chance” category, meaning that there is not a strong enough climate signal in these areas to shift the odds, so they have an equal chance for above-, near-, or below-normal temperatures and/or precipitation.
So in short, NOAA forecasters are likely already packing their bags to ski and the Northern Rockies and Michigan this winter.
Drought will likely persist through the winter in many regions currently experiencing drought, NOAA forecasters indicate, including much of California and the Southwest. Drought is expected to persist and spread in the southeastern U.S. and develop in the southern Plains. New England will see a mixed bag, with improvement in the drought conditions in western parts and persistence to the east. Drought improvement is also anticipated in northern California, the northern Rockies, the northern Plains and parts of the Ohio Valley.
This seasonal outlook does not project where and when snowstorms may hit or provide total seasonal snowfall accumulations, NOAA cautions. Snow forecasts are dependent upon the strength and track of winter storms, which are generally not predictable more than a week in advance. However, La Niña winters tend to favor above average snowfall around the Great Lakes and in the northern Rockies and below average snowfall in the mid-Atlantic.
The private weather service Accuweather issued its winter outlook last month, predicting a cold and snowy winter in the Northeast, in contrast to NOAA’s prediction for equal probability for above- or below-normal temperatures and precipitation throughout most of that region.