In today’s somewhat surprising climate news, NOAA announced that they are canceling the La Niña watch that has been in place for several months. While colder than normal conditions have been seen in the Eastern Pacific Ocean near the equator for a while, they have not been strong enough for long enough to constitute an official La Niña. The wind bursts that strengthen colder than normal waters into a full-fledged La Niña have not occurred this year, and the predictions are for temperatures in that region to slowly warm over the next few months, heading back to neutral territory. There is still an approximately 40 percent chance a La Niña could happen, but the percentages are no longer high enough to warrant the Watch.
What does this mean for the climate of the Southeast in the coming months? For fall, the cooler than normal waters are likely to continue to cause La Niña-like warmer and drier than usual weather. In either La Niña or neutral conditions, tropical activity is more likely than in El Niñ0. But as the ocean temperatures go back towards normal, this will become less likely. If neutral conditions occur this winter, then prediction of Southeast climate will become more difficult, since there is no strong ENSO signal and other factors like oceanic temperatures and wave patterns in other parts of the globe become more important. We do know that in ENSO-neutral winters, the probability of a severe freeze is significantly greater than during El Niño or La Niña winters.
Here is a link to the NOAA ENSO Diagnostic Discussion: https://www.cpc.ncep.noaa.gov/…/analysis_monitoring/enso_adv…
NOAA explains the change in their ENSO blog at https://www.climate.gov/news-features/blogs/enso/september-2016-enso-update-cooling-our-heels.
KXAN has a good article explaining the switch in the forecast at https://kxan.com/blog/2016/09/08/la-nina-watch-dropped-get-ready-for-anything-this-winter/.
Mashable also points out that with La Niña fizzling, record warm temperatures for the globe this year are more likely. You can read this at https://mashable.com/2016/09/08/la-nina-watch-canceled-global-warming/#_ZbHrcvEZZqX.
