FLORIDA, United States, Wednesday May 23, 2018 – American scientists studying past and future weather patterns have warned hurricane conditions could get bigger, stronger and wetter.
Researchers at the National Centre for Atmospheric Research (NCAR) have published a detailed analysis of how 22 recent hurricanes would change if they instead formed near the end of this century. And while each storm’s transformation would be unique, on balance, the hurricanes would become a little stronger, a little slower moving, and a lot wetter.
In one example, Hurricane Ike — which killed more than 100 people and devastated parts of the US Gulf Coast in 2008 — could have 13 per cent stronger winds, move 17 per cent slower, and be 34 per cent wetter if it formed in a future, warmer climate.
Other storms could become slightly weaker (like Hurricane Ernesto) or move slightly faster (like Hurricane Gustav). None would become drier. The rainfall rate of simulated future storms in the study increased by an average of 24 per cent.
The study, led by the National Centre for Atmospheric Research (NCAR) and published in the Journal of Climate, compares high-resolution computer simulations of more than 20 historical, named Atlantic storms with a second set of simulations that are identical except for a warmer, wetter climate that is consistent with the average outcome of scientific projections for the end of this century.
“Our research suggests that future hurricanes could drop significantly more rain,” said NCAR scientist Ethan Gutmann, who led the study. “Hurricane Harvey demonstrated last year just how dangerous that can be.”
Harvey produced more than four feet of rain in some locations, breaking records and causing devastating flooding across the Houston area.
“This study shows that the number of strong hurricanes, as a percent of total hurricanes each year, may increase,” said Ed Bensman, a program director in the National Science Foundation’s Division of Atmospheric and Geospace Sciences, which supported the study. “With increased development along coastlines, that has important implications for future storm damage.”
The scientists created an algorithm to detect and track hurricanes within the vast amount of data. They identified 22 named storms that appear with very similar tracks in both the historic and future simulations, allowing them to be more easily compared.
As a group, the storms in the future simulation had six per cent stronger average hourly maximum wind speeds than those in the past. They also moved at a 9 per cent slower speed and had a 24 per cent higher average hourly maximum rainfall rate. Average storm radius did not change.
But each storm was unique.
Still, there was one consistent feature across storms: They all produced more rain.
Other research has suggested that fewer storms may form in the future due to increasing atmospheric stability or greater high-level wind shear, though the storms that do form are apt to be stronger.
“It’s possible that in a future climate, large-scale atmospheric changes would make it so that some of these storms might never be able to form,” Gutmann said. “But from this study we get an idea of what we can expect from the storms that do form.