Photograph by JOEL SARTORE, Nat Geo Image Collection
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A National Park worker surveys damage in southern Florida after Hurricane Andrew in 1992. A lot has changed about our understanding of the storms since then.

Photograph by JOEL SARTORE, Nat Geo Image Collection

3 Advances in Hurricane Science Could Make Us Safer

Twenty-five years since the devastation of Hurricane Andrew, weather forecasting is providing new insights—as Hurricane Harvey approaches Texas.

Twenty-five years ago today, the hurricane of South Florida’s nightmares arrived. Greedily inhaling energy from the warm, late summer waters, Hurricane Andrew ripped into southern Dade County just before dawn on August 24, 1992 with a ferocity almost beyond measurement.

The small, intense storm’s 165-mph winds altered the landscape and blasted away civilization for weeks.

“One-hundred-foot-long concrete beams flew 100 yards, plywood and two-by-fours split palm trees, flying boards penetrated concrete-block walls and killed people. All kinds of unimaginable things happened that had never been seen before,” said The Weather Channel meteorologist Bryan Norcross, author of My Hurricane Andrew Story. Norcross became a broadcasting legend when he and a WTVJ-TV news crew in Miami stayed on the air during Andrew’s landfall offering viewers advice and encouragement as they rode out the storm.

A U.S. Air Force base and a new baseball stadium in Homestead—about 35 miles south of Miami—were destroyed. In some places total devastation of homes and businesses was visible from horizon to horizon. Florida City, a small town just south of Homestead where Andrew’s most powerful winds came ashore, looked like it had been shelled by artillery.

But Hurricane Andrew did more than level buildings. It prompted extensive research and major changes in how the U.S. monitors and forecasts developing hurricanes and how emergency management responds after a storm makes landfall. A quarter-century after Andrew, forecasters and emergency management directors are armed with new tools to help them more accurately predict the track of a hurricane and warn those in its paths of the dangers they’re likely to face.

Hurricanes 101

These tools are coming into focus even more this August, as the Atlantic hurricane season heats up for the next few months, and as Hurricane Harvey approaches Texas and has the chance to become a hurricane.

Among those developing hurricane science tools are:

· Two recent computer models—known as HMON and HWRF—that allow more accurate forecasting of a hurricane’s future track. In 1992, forecasters tried to project a hurricane’s likely track three days in advance. The new computer models allow forecasters to predict the hurricane’s track five days in advance. Phil Klotzbach, a researcher at Colorado State University, said the three-day forecast accuracy has “improved dramatically” since 1992, when the average forecast error was about 270 miles. “Last year, the average (three-day) forecast track error was about 90 miles,” he said. Frank Marks, Director of the National Oceanic and Atmospheric Administration’s Hurricane Research Division in Miami, said NOAA would like to eventually extend the track forecast to seven days in advance.

· Storm surge watches and warnings. A hurricane’s storm surge is a mound of water piled up by the storm’s winds. Even minimal hurricanes can create storm surges that cause heavy damage and deaths. And the surge can affect coastlines even if the hurricane doesn’t come ashore. Hurricane Matthew pushed a storm surge ashore from Florida to Virginia as it pounded up the Atlantic coast in October 2016. Starting this year, NOAA will provide more detailed forecasting of storm surges.

· A two-day warning of when high winds in advance of a hurricane’s center are likely to affect an area. This warning will help residents prepare for the storm or evacuate and emergency managers plan their responses. Marks said NOAA researchers are working to measure “things that matter to the public—flooding, tree damage, power lines down.”

NOAA researchers also want to improve forecasting the likelihood that a hurricane will rapidly intensify, as Hurricane Andrew did as it approached landfall in Florida. Andrew exploded from a minimal hurricane with peak winds of 75 mph to a monster with winds exceeding 165 mph in only about 36 hours.

Despite intensive research into the phenomenon of rapid intensification, however, answers have been slow in coming.

“It’s a big problem,” Marks said.

Despite its ferocity, a powerful hurricane can be delicate, and slight changes in its environment—such as cooler water that deprives it of energy or upper-level winds that disrupt its circulation—can greatly affect it. The atmosphere around the storm is constantly in motion and changing moment by moment, and incorporating all these factors into a forecast that accurately predicts whether it will rapidly gain strength is very difficult.

“Our ability to predict intensification is not quite there yet,” Marks said. “We’re getting there.”

The Weather Channel’s Norcross said that even with the improvements of the past 25 years, it still would be “very unlikely” that the kind of intensification that Hurricane Andrew experienced could be forecast today.

Coasts at Risk

Norcross also is concerned about the vulnerability to hurricanes of U.S. coastal cities—especially Miami and New Orleans.

“Every coastal city in the U.S. is more vulnerable to a powerful hurricane than it was 25 years ago,” Norcross said. “That, in spite of the fact that the building code (in South Florida) is extremely strong—the strongest in the world against hurricanes.”

The reason is simple, he said—“so many more people with so much more wealth and property.” And the problem is exacerbated by rising sea level, which will make storm surges more deadly and destructive.

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Seen through a lighthouse, Andrew's destruction is apparent on Boca Chita Island.

Despite the advances since Hurricane Andrew, Norcross fears that the passage of 25 years has diminished the impact of Andrew’s brutal lessons.

“Everybody that knows anything about hurricanes knows that Hurricane Andrew was a terrible hurricane,” he said. “But my experience tells me that the epic nature of the event is lost on most people in South Florida, and indeed, most meteorologists I know who were not intimate with the storm. Andrew has become another line on a list of storms in the history books.”

Listen to IPPY Award-winning author Willie Drye talk about his latest book, For Sale—American Paradise: How Our Nation Was Sold An Impossible Dream In Florida, on NPR affiliates WUNC, Chapel Hill and WLRN, Miami. Visit his blog, Drye Goods, now in its 10th year. Follow him on Facebook.