The National Oceanic and Atmospheric Administration has released its yearly Winter Outlook which tells of a second winter in a row which will be affected by La Niña which will bring continued drier and warmer than average weather in the Southern Plains and colder and wetter conditions in the Pacific Northwest.
The one missing piece is the impact that the Arctic Oscillation will have on conditions throughout the coming months, deemed a ‘wild card’ by NOAA.
La Niña returned in August and is expected to continue strengthening through the upcoming winter.
A La Niña event – a part of the El Niño-Southern Oscillation – is linked to colder water temperatures in the tropical Pacific Ocean, which in turn impact weather conditions throughout the world.
“The evolving La Niña will shape this winter,” said Mike Halpert, deputy director of NOAA’s Climate Prediction Center. “There is a wild card, though. The erratic Arctic Oscillation can generate strong shifts in the climate patterns that could overwhelm or amplify La Niña’s typical impacts.”
Highlights of the U.S. Winter Outlook (December through February) include:
- Pacific Northwest: colder and wetter than average. La Niña often results in below-average temperatures and increased mountain snow in the Pacific Northwest and western Montana during the winter months. This may set the stage for spring flooding in the Missouri River Basin;
- California: colder than average with odds favoring wetter than average conditions in northern California and drier than average conditions in southern California. All of the southern part of the nation are at risk of having above normal wildfire conditions starting this winter and lasting into the spring;
- Northern Plains: colder and wetter than average. Spring flooding could be a concern in parts of this region;
- Southern Plains and Gulf Coast States: warmer and drier than average. This will likely exacerbate drought conditions in these regions;
- Florida and south Atlantic Coast: drier than average, with an equal chance for above-, near-, or below-normal temperatures. Above normal wildfire conditions;
- Ohio and Tennessee Valleys: wetter than average with equal chances for above-, near-, or below-average temperatures. Potential for increased storminess and flooding;
- Northeast and Mid-Atlantic: equal chances for above-, near-, or below-normal temperatures and precipitation. Winter weather for these regions is often driven not by La Niña but by the Arctic Oscillation. If enough cold air and moisture are in place, areas north of the Ohio Valley and into the Northeast could see above-average snow;
- Great Lakes: tilt toward colder and wetter than average;
- Hawaii: Above-average temperatures are favored in the western islands with equal chances of above-, near-, or below average average precipitation. Statewide, the current drought is expected to continue through the winter. Drought recovery is more likely over the windward slopes of the Big Island and Maui;
- Alaska: colder than average over the southern half of the state and the panhandle with below average precipitation in the interior eastern part of the state.