Using this simulated dataset, called IRIS, the researchers selected the storms that made landfall along a track similar to Milton's. Using this, they show that the warming climate has increased the frequency of storms of Milton's intensity by 40 percent. Accordingly, the maximum wind speeds of similar storms have increased by about 10 percent. In Milton's case, this means that in the absence of climate change, the storm would likely have made landfall as a Category 2 storm, rather than a Category 3 storm, as it actually was.
Rainfall
The lack of complete meteorological data caused a problem in analyzing rainfall in Milton. The researchers ultimately had to analyze rainfall in general. Using four datasets tracking rainfall in these regions, they tracked the link between extreme rainfall and warming climate to estimate how much more frequent extreme events will occur in a world that is now 1.3°C warmer than it was in pre-industrial times.
They focus on extreme single-day rainfall events from June to November, specifically looking at one-in-ten-year and one-in-a-hundred-year events. Both studies produced similar results, suggesting that heavy single-day rain showers are about twice as likely in the current climate, and that the most extreme rain showers are between 20 and 30 percent more intense.
These results came from three of the four datasets used, which yielded broadly similar results. The fourth dataset they used suggested a much stronger effect of climate change, but because it was not consistent with the rest, these results were not used.
As with the Helene analysis, it is worth noting that this work represents a specific snapshot along a long-term warming trajectory. In other words, it's looking at the impact of 1.3°C of warming at a time when our emissions are almost at the point where they're committing us to at least 1.5°C of warming. And that will tipping the scales even further in favor of extreme weather conditions like this.
