Update: Weak La Niña is still expected to emerge

La Niña conditions are still favored to develop in the coming months, but the event should remain weaker and shorter than other historic La Niña winters, according to a new update released by NOAA on Thursday.

This means that there should be less influence on global weather patterns, including in the US.

La Niña occurs when sea surface temperatures in the central and east-central equatorial Pacific reach a cooler-than-average threshold that can influence weather patterns worldwide. However, if the La Niña that develops is on the weaker side, there would be fewer impacts.

(MORE: What is La Niña? A deeper dive).

Neutral conditions remain in place, but a La Niña watch is still in effect. Waters in the eastern and central Pacific near the equator have remained at near-average temperatures this month. This means that neither El Niño nor its counterpart La Niña is in progress.

Sea surface temperatures in the equatorial Pacific are currently a mix of cooler and warmer waters, as shown in the map below, indicating that neutral conditions are still in place.

A La Niña watch remain in effect, NOAA said. That’s because the waters in this region are still expected to cool and last long enough to reach the threshold for a La Niña event.

NOAA said in its November update, “The team still favors the onset of La Niña, but it is likely to remain weak and of shorter duration than other historical episodes. A weak La Niña would be less likely to result in conventional winter impacts.”

Assuming La Niña forms, it is expected to last through January to March next year.

La Niña can affect both winter temperature and precipitation patterns. Below is a look at the typical winter temperatures and precipitation patterns that La Niña has historically produced.

Keep in mind, given the forecast for a weak event this winter, these patterns may be less pronounced than normal, as noted by NOAA earlier. In addition, other factors in the atmosphere can override the influence of La Niña during periods in the winter.

Temperatures: The north-central United States tends to be colder than average during La Niña winters. The south often sees above-average temperatures, but that doesn’t mean there won’t be periods of colder weather.

In this case, winter is defined as the three-month period from December to February.

Precipitation: La Niña usually brings wetter than average winter conditions to the Pacific Northwest and Ohio Valley, while the southern tier of the country tends to be drier.

Jennifer Gray is a weather and climate writer for weather.com. She has covered some of the world’s biggest weather and climate stories for the past two decades.