The globe’s hurricanes have seen a striking slowdown in their speed of movement across landscapes and seascapes over the past 65 years, a finding that suggests rising rainfall and storm-surge risks …
Slower-moving storms will rain more over a given area, batter that area longer with their winds and pile up more water ahead of them as they approach shorelines, said Jim Kossin, a scientist with the National Oceanic and Atmospheric Administration and the study’s author.
Hurricanes are traveling more slowly — which makes them even more dangerous - The Washington Post
In February 2018 Waikawa Beach was affected by the remains of Tropical Cyclone Gita, which eroded the coast, especially by the river mouth. Of course any storm loads up the river and adds to our high groundwater. That 15% slowdown in our region is likely to make problems with erosion, river levels and ground water worse. It could be good news for our rainwater tanks though.
The study quoted above goes on to talk about the impact of climate change on storms too:
…it is expected that hurricanes will rain about 7 to 10 percent more per degree Celsius (1.8 degrees Fahrenheit) of warming, as the atmosphere retains more water vapor, Kossin explained. …
These two trends ought to work in tandem to make today’s storms much worse rainmakers.