There are signs pointing towards El Niño developing over the summer. The models aren’t very strong with the nino right now, but historically after 2nd and 3rd year Ninas we have seen stronger ninos. After the 3 year Nina ending in 2001 and the 2 year Nina ending in 2009, a moderate or strong El Niño developed! There is a lot of warm water below the surface in the western enso 4 region, these waters are as much as 6 degrees Celsius above normal. It will spread out as it comes up so we won’t see a
Apologies for getting to this rather late in the discussion, was going to answer in the morning but I'm having some trouble sleeping anyway. Lengthy volcano nerd post incoming, feel free to skip this post to get back to ENSO discussion .
To be honest, regarding Hunga Tonga you all are better equipped to debate its impacts than I am at this point, as it is very much not the classic 'Pinatubo style' atmospheric SO2 bomb sort of eruption that imparts a well studied downward forcing of surface