After a lot of “waffling” over the summer and fall, NOAA is now saying that La Niña is indeed favored this fall/winter.
This news comes after the meteorological organization downgraded the chances of the event back in early September. However, according to the latest ENSO post, The La Niña watch is back in effect with a 70% chance of the phenomena affecting the western US this fall before those chances fall to 55% for the winter months.
“La Niña is favored to develop (~70% chance) during the Northern Hemisphere fall 2016 and slightly favored to persist (~55% chance) during winter 2016-17.” – NOAA
The most recent news from NOAA is all thanks to the atmosphere reacting to cooler than normal sea-surface temperatures. That interaction is most evident in how the jet stream and trade winds reacted to the cooling temperatures by speeding up and moving slightly further north.
“Atmospheric anomalies across the equatorial Pacific edged toward La Niña during September, with a stronger tendency toward La Niña late in the month” – NOAA
That said, La Niña events are seasonal by nature, meaning these conditions must persist for several months before this is considered a La Niña at all.
Find the entire ENSO post here: Antici…pation – October 2016 ENSO forecast