Q&A: ENSO
Eugene asked:
"Last Tuesday, you guys reported this ENSO chart:
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Your comment says that 60 days below the -0.5 threshold forms the La Nina.
Water temperature has been below the line at least since early July.
However, NOAA says "La Niña is favored to emerge in September-November (60% chance)".
So, why is it not a La Nina event already but a chance for it?"
Roger’s reply: