La Niña conditions have developed and may last through the winter, according to a new report released Thursday from NOAA.
This is a weak La Niña and it’s now in place, which could mean that the impacts may not be as strong as a typical La Niña winter. Generally, in a La Niña winter you would expect warmer and drier than average conditions in the southern tier, while the northern tier experiences cooler and wetter conditions.
NOAA says there is a 55 percent chance that La Niña conditions will persist through February.
La Niña conditions were observed during October and into early November, meaning cooler than average sea surface temperatures stretched across most of the eastern and central equatorial Pacific Ocean.
Overall, the ocean and atmosphere system reflected weak La Niña conditions, according to the report.
Forecast computer models and the current atmospheric and oceanic conditions favor La Niña conditions continuing through the winter. However, La Niña will likely be short-lived, with a return to neutral, neither La Niña or El Niño, conditions in the spring.
Last winter featured one of the strongest El Niño events on record, which is when warmer than average sea surface temperatures are found across the equatorial eastern and central Pacific. It is not uncommon for a La Niña to follow El Niño events a few months later.
After the record strong El Niño of 1997-98, La Niña almost immediately set in the next summer and reached moderate-to-strong intensity before finally ending in spring 2001.
A similar situation happened following the strong El Niño of 1972-73. However, neutral conditions followed three other strong El Niños of 1982-83, 1965-66 and 1957-58.