According to NOAA’s latest ENSO post, we are on the verge of going back into a La Nina, with a 70-80 percent chance of occurrence over the winter. All of the conditions are ripe for us to cross the magic threshold of ocean temperatures more than 1/2 degree C below the long-term average. You might wonder how they decide that a La Nina is officially occurring. The blog post gives a good description of how that determination is made and how that will affect our winter. Check it out at https://climate.gov/news-features/blogs/enso/september-2021-enso-update-feeling-groovy.
