Storm risk is not just a category
Hurricane Debby’s approach to the possibility of up to 30 inches of rain in parts of the Southeast illustrates the problem meteorologist Barry Goldsmith has struggled with of late back in 2012.
Goldsmith, a meteorologist with the National Weather Service in Texas, said he wanted a “sticky slogan” to help a wider audience understand why the traditional wind group system for writing hurricanes without taking into account how much rain there may be or how damaging the storm will be. rise can be. At the 2012 National Hurricane Conference, he said he gave this quote: “There’s more to a story than a team.”
“That’s good news,” Brian McNoldy, a senior research scientist at the University of Miami’s Rosenstiel School, wrote about X in July. He has used the phrase over and over for years, hoping to impress people with how heavy the rain is and how strong the storm is.
The message has proven true time and time again, and it’s especially true for Debby. The actual storm threat calls for gusty winds and heavy rain from Florida’s Gulf Coast to Charleston, South Carolina.
“This is another example of a storm where the main effects are going to be from the water, rather than the wind,” said James Franklin, retired director of the National Hurricane Center’s National Hurricane Center. of Hurricane. “So while the forecast component (1/2 boundary) will be significant to the immediate right of the landfall, there will be significant impacts elsewhere.”
That’s not to say the Saffir-Simpson Hurricane Wind Scale system isn’t useful, especially for personal preparations. “Group 5 makes you broke, rain and wind,” Franklin wrote in X in August, adding that he was uncomfortable with the message that the group doesn’t matter. “The club is a very good representative of the worst spirits you can have.”
But classifying hurricanes doesn’t tell the whole story. It doesn’t provide rain, rise, or forward momentum, experts like Craig Fugate, former director of the Federal Emergency Management Agency, noted.
In some cases, people may mistakenly feel safe with low-level storms, thinking, for example, that it’s just “Cat 1,” experts warn.
Why forward momentum is important
Debby’s signal will not include a wall of water up to 10 feet above land that could reach the coast near Florida’s Big Bend Sunday night and Monday afternoon. It also doesn’t offer the kind of flash flooding that would match the level of forecast rain along Debby’s path.
“That’s the question, where is it going to rain,” Fugate told USA TODAY on Sunday. “Based on the current forecast, some areas could see more than a foot of rain as the storm moves through (Northeast Florida.)” And Fugate noted that even more is limited to coastal South Carolina. and northeast Georgia.
At one point Sunday, coastal forecasts for South Carolina and Georgia said up to 10 inches of rain was possible with the storm, but by mid-afternoon, the weather service lower that level.
A tornado moving at 20 mph leaves much less damage than a tornado that hits an area if it stagnates or crawls at 8 to 10 mph. A slow-moving storm can also drop more rain than a fast-moving storm.
Hurricane scientists have found in recent studies that Atlantic storms appear to be slowing down before they make landfall, piling up the problems of rain and flooding.
Climate change:2024 hurricane season breaks record, due to hot water
Should air balance be changed?
Many researchers have suggested looking at different ways to accurately convey risks.
Jennifer Collins, a professor in the School of Geosciences at the University of South Florida, has written a joint study on how the public perceives wind speed compared to other proposed methods. He was a co-author of a paper in 2021 that proposed the Tropical Cyclone Severity Scale, incorporating wind speed, rainfall, and storm intensity to improve public perception of hazards.
Debby is “another example of how the type of storm doesn’t really reflect the severity of the impacts,” Collins said Sunday. “I am very concerned about the potential for flooding, especially in areas affected by past hurricanes.”
Collins said it’s important for the public to look at all the other products the hurricane center displays on its website.
While modeling a storm with wind conveys the threat of its strongest winds, it tells you very little about the storm’s size or the threat of precipitation, said Phil Klotzbach, a senior research scientist at Colorado State University. “We argue that pressure is a better metric to classify hurricanes.”
It better correlates with injuries and damage caused by storms and gives you an idea of the size of the storm as well as the strength of the storm, Klotzbach said Sunday.
Rain should be kept separate, he said, in part because of difficulties in conveying the difference in flood power, such as a slow-moving storm or a very large storm.
Some examples of tropical storms or ‘Cat One’ hurricanes
Hurricane Beryl – Category 5 in the Caribbean, Beryl made landfall on July 8 near Matagorda, Texas, as a Category 1. It caused widespread flooding with a total of 13 to 14 inches of rain, leaving millions they have no electricity. A week after the storm, at least 300,000 customers in the Houston metro area remained without power.
Tropical Storm Allison – In June 2001, Allison flooded Texas with 40 inches of rain in Houston.
Debbie in 2012 – Tropical Storm Debby caused an estimated $250 million in damage and killed eight people.
Dinah Voyles Pulver covers climate change and the environment for USA TODAY. He has been writing about hurricanes, storms and extreme weather for over 30 years. Reach him at dpulver@gannett.com or @dinahvp.
#Storm #risk #category