FWIW, this eruption released less ash and SO2 than even St. Helens in 1980, let alone Pinatubo in 1991. Its effect on the climate is probably far less that we saw in 1992 with Pinatubo. Also, volcanoes that erupt in the tropics (e.g. Tonga) tend to result in +NAOs and warming, at least for the first 9 months or so, before any cooling sets in. That said, I'm not sure what difference a winter-erupting volcano would make, as opposed to the summer eruption of Pinatubo, whose cooling was not apparent here until the following March.