Climate Change and Heavy Rainfall Events in Hawai'i

Climate Change and Heavy Rainfall Events in Hawai'i
K. Hamilton (IPRC)
Global climate models have typically represented the Hawaiian Islands as a single land grid-box or ignored Hawaii
entirely. Now the Japanese Meteorological Research Institute has run the first multidecadal integrations of a global
model with horizontal resolution fine enough to represent at least the main topographic features of the Hawaiian
Islands. The simulated annual-mean rainfall reproduces observed maxima on the east and west sides of the Big
Island (left: contours at 1, 1.5, 2, 3, 4, 5 ….mm/day). A histogram of simulated hourly rainfall rates at all the land
grid-boxes in Hawaii for present day and for the late 21st century (right) projects that the heaviest rainfall events will
become more frequent. This would be an adverse impact of global warming as flash flooding is already a significant
hazard in Hawaii that can inflict millions of dollars in property losses.