Winter 2016-17 Outlook: Weak La Niña May Bring Colder Temperatures to the East, Dry Conditions in the South

Linda Lam
Published: October 20,2016
Winter 2016-17 may bring colder-than-average temperatures to the East early on, but this winter may end up warmer than average overall, according to an outlook released by The Weather Company, an IBM Business.
A weak La Niña is expected to develop, which would result in colder temperatures in the East and warmer temperatures in the West, which flips the pattern of the last several months, said Dr. Todd Crawford, chief meteorologist with The Weather Company.
Last winter was the Lower 48's warmest December-February period in the 121 years on record, according to NOAA's National Centers for Environmental Information.
(RECAP: Record Warmest U.S. Winter)
NOAA's winter outlook, also released Thursday, indicates that La Niña will also be a factor this winter. This would result in more preciptation in the northern states and less in the South, compared to last winter.
Here are the outlooks from both The Weather Company and NOAA.

The Weather Company Forecast

There are indications that the East may see colder than average temperatures this winter, especially earlier in the season.
However, climate computer models are depicting an atmospheric response to the expected weak La Niña in January, which would allow warmer temperatures in the East with colder conditions developing in the Pacific Northwest.
In the Southwest, there will most likely be persistent above-average temperatures, while the Pacific Northwest is likely to see the best chance for persistent cold, especially in January and February.

December 2016 - February 2017 temperature outlook from The Weather Company, an IBM Business.

Last year, El Niño was an important factor in the winter forecast. This year there is a good chance of a weak La Niña playing a role. However, the warm northeastern Pacific sea surface temperatures, a lack of background blocking and lingering warmth from El Niño also all need to be considered.
One winter that also featured a weak La Niña and warm sea surface temperatures in the northeastern Pacific is 1995-96, according to Crawford. However, there are differences that will likely make this winter warmer than 1995-96.
"The Pacific sea surface temperature pattern for the upcoming winter will likely be a fairly close match to that observed in 1995-96, a well-known stormy/cold winter in the East, but this colder signal will be strongly tempered by (1) significant warm atmospheric 'hangover' from recent historically strong El Niño and (2) reduced chances of high-latitude blocking," Crawford said.
(MORE: Winter Storm Central)
There has not been high-latitude blocking, which locks in Arctic air, in the central and eastern U.S. in the last three winters, and that is not expected this winter either.
It is important to remember that even if it is a warmer-than-average winter there will still be surges of cold temperatures, along with impactful winter storms.
(MORE: Winter Storm Names 2016-2017)

NOAA's Forecast

The temperature outlook from NOAA agrees with TWC outlook that the best chance for above-average temperatures this winter is in the Southwest. However, there are differences in how far east and north the above-average temperatures will reach.
NOAA extends the chance for warmer-than-average temperatures through the Southeast and also introduces an area in the northern Plains and Upper Midwest where colder than average temperatures are a possibility.
Portions of the Pacific Northwest, Midwest and Northeast could have equal chance of experiencing above- or below-average temperatures.

December 2016 - February 2017 temperature outlook from NOAA.

In terms of preciptation, NOAA expects portions of the northern tier -- including portions of the Northwest, northern Plains and Great Lakes -- to see above-average precipitation this winter because of a more active northern jet stream.
(MORE: When the First Snow Usually Falls)
Much of the southern tier is expected to be drier than average, with the greatest chance of below-average precipitation from central Texas along the northern Gulf Coast into northern and central Florida.
This is not good news for portions of the South and Southeast, which are experiencing drought conditions. Alabama and Mississippi are experiencing abnormally dry conditions and almost 30 percent of Georgia is in extreme drought, according to the drought monitor released Oct. 20.
According to NOAA, "Drought is expected to persist and spread in the southeastern U.S and develop in the southern Plains. Drought improvement is anticipated in northern California, the northern Rockies, the northern Plains and parts of the Ohio Valley."

December 2016 - February 2017 precipitation outlook from NOAA.

In areas not covered in green or brown in the above map, there are equal chances of seeing below-or above-average precipitation.
According to NOAA, a La Niña winter could bring above-average snowfall around the Great Lakes and in the northern Rockies, with below average snowfall in the mid-Atlantic region.
The primary factors in both the precipitation and temperature outlooks from NOAA are the weak La Niña predicted to develop and climate forecast models. Global sea surface temperatures also were considered.
MORE: Mid-May Snow in Midwest, Northeast (PHOTOS)