After 10 Years, Andrew Gains Strength

Scientists now believe Hurricane Andrew’s winds were at least 10 mph faster than previously thought – making it only the third Category 5 storm to hit United States in recorded history.

Hurricane forecasters and researchers planned to announce Wednesday the change of the 1992 hurricane’s intensity, said Frank Lepore, spokesman for the National Hurricane Center in Miami.

Andrew was recorded as having 145 mph maximum sustained winds, which made it a strong Category 4 storm on the Saffir-Simpson scale. But researchers now believe it crossed the 155 mph threshold for a Category 5 – the strongest on the scale – with some saying its winds may have reached 165 mph.

A six-member committee deliberated for several months and studied the evidence of new technology before concluding that Andrew’s intensity needed to be upgraded.

When Andrew hit South Florida on Aug. 24, 1992, it killed 43 people and caused $30.5 billion in damage, making it one of the most expensive natural disasters in the United States.

It also destroyed the equipment used to measure wind speed and storm intensity. The anemometer at the National Hurricane Center in Miami recorded a peak gust of 164 mph before it was disabled.

To determine the maximum sustained wind speed, airplanes took measurements at 10,000 feet and forecasters derived the 145 mph speed at the surface.

But advances in technology have improved the formulas forecasters use to estimate wind speed, said James Franklin, a hurricane specialist at the National Hurricane Center.

Using the new formula, Franklin said at a recent conference, Andrew’s surface winds would be 165 mph.

Bob Sheets, who was the hurricane center’s director during Andrew, said forecasters thought they were being conservative 10 years ago when they estimated the wind speed as 145 mph to 175 mph.

But some engineers thought they had exaggerated the wind speed.

“We had some disagreements there and they have continued right up to today,” Sheets said.

While the change in classification may be of interest to scientists, it will have little or no impact on the general population.

The change in classification will have little affect on property insurance rates, said Sam Miller, the Florida Insurance Council’s vice president.

“The key is not the category it was or even how fast it was going,” Miller said. “The key is how much damage it did.”

The insurance industry already treats Andrew as the worst natural disaster that has hit the United States, Miller said. Revising the wind speed will not change past insurance pay outs and is not likely to change future rate calculations, he said.

Sheets agreed that changing Andrew from a Category 4 storm to a Category 5 will only affect hurricane statistics. Only two other Category 5 storms are known to have hit the U.S. coast – Hurricane Camille in 1969 and the 1935 Labor Day storm that struck the Florida Keys.

“It really doesn’t matter,” Sheets said. “We’re only talking about a 5 to 10 mph difference. As far as the people are concerned, it doesn’t matter what you call it. We know what it did.”

Associated Press writer Tony Winton contributed to this report.

Hurricane categories based on Saffir-Simpson scale

Hurricanes are ranked 1 to 5 according to what is known as the Saffir-Simpson scale of strength:

Category 1 – Hurricane has central barometric pressure of 28.94 inches or more and winds of 74 mph to 95 mph, is accompanied by a 4-foot to 5- foot storm surge and causes minimal damage.

Category 2 – Pressure 28.50 inches to 28.93 inches, winds from 96 mph to 110 mph, storm surge 6 feet to 8 feet, damage moderate.

Category 3 – Pressure 27.91 inches to 28.49 inches, winds from 111 mph to 130 mph, storm surge 9 feet to 12 feet, damage extensive.

Category 4 – Pressure 27.17 inches to 27.90 inches, winds from 131 mph to 155 mph, storm surge 13 feet to 18 feet, damage extreme. Hurricane Georges, when it went through the Caribbean in late September 1998 and Hurricane Hugo were Category 4 storms.

Category 5 – Pressure less than 27.17 inches, winds greater than 155 mph, storm surge higher than 18 feet, damage catastrophic. Experts now say 1992’s Hurricane Andrew was a Category 5 storm. Only two other Category 5 storms – the 1935 hurricane in the Florida Keys and Camille in 1969 in Louisiana and Mississippi – have hit the United States.

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