Experts ponder storm categories

Hurricane forecasts need refining so people will better understand when to evacuate, agreed experts.

BY HEATHER MOYER | WASHINGTON, D.C. | March 11, 2005



"Evacuees often travel much farther than necessary, which contributes to road congestion."

—Dr. Earl J. Baker


Hurricane forecasts need refining so people will better understand when to evacuate, agreed experts at the Disasters Roundtable held this week at The National Academies.

The current Saffir-Simpson hurricane intensity scale - which categorizes storms based solely on wind strength - is not an adequate forecasting tool, said Dr. Louis Ucellini, director of the National Weather Service's National Centers for Environmental Prediction.

Categorizing a storm based off its wind speed does not offer the public enough information, Ucellini said.

Because current hurricane categorizations don't include predictions of rainfall amounts, storm surges, and several other factors, the need to evacuate is not always clear to some residents, said several of his colleagues.

Hurricane Charley seemed to surprise some residents when it strengthened rapidly and suddenly shifted tracks.

"(Hurricane) Charley's sudden strengthening is why we encourage people to evacuate," said Ucellini, noting Charley went from a Category 2 storm to a Category 4 storm within 12 hours before hitting Florida.

He added that the residents of southeast Florida should not have been surprised when Hurricane Charley suddenly shifted its track and made landfall by Punta Gorda instead of Tampa. "They were within the cone of uncertainty," explained Ucellini, referring to the shape of the hurricane's predicted track.

Another factor that makes evacuation planning difficult is outdated flood plain maps, said Dr. Earl J. Baker, a Florida State University professor whose research includes human response to environmental hazards. But there is good news on the horizon - a new type of surface radar is helping emergency managers map out ground levels so they know where to place evacuation shelters and just who should be evacuated.

"Evacuees often travel much farther than necessary, which contributes to road congestion," said Baker, pointing to a slide photo of the extreme road congestion in South Carolina during the evacuation before Hurricane Floyd.

In addition to evacuation challenges, experts also discussed building codes, the recovery process, climate change, and how demographics affect disaster recovery. The Disasters Roundtable, held annually, was entitled "Lessons Learned between Hurricanes: From Hugo to Charley, Frances, Ivan and Jeanne."

Hurricanes cost the U.S. an average of $5 billion each year, said Dr. Stephen Leatherman, director of Florida International University's Hurricane Research Center. Hurricanes are the costliest natural disasters that hit the country, he added.

All four major hurricanes of the 2004 season - Charley, Frances, Ivan and Jeanne - are now in the Hurricane Insurance Information Center's top ten costliest U.S. hurricanes.

When discussion turned to damage levels, several speakers noted that it is obvious in disaster zones which homes were built before certain building codes were enacted. Timothy Reinhold of the Institute for Business and Home Safety ticked off a list of problematic features that contribute to damage during hurricanes.

"Garage doors continue to be a major problem," he explained, showing a slide of a crumpled door versus a slightly damaged one that was up-to-code for hurricane force winds. He added that double doors are also easily blown out during a hurricane, as are weakly-constructed store fronts and commercial overhangs.

Earlier in the conference, Leatherman had noted that some estimates state that 50% of the damage done during 1992's Hurricane Andrew could have been prevented with hurricane shutters.

The keys to helping decrease the amount of damage done by hurricanes, said Reinhold, continue to be up-to-date building codes as well as builders who understand and appreciate the risk. The needs include support for wind-field mapping, which helps builders know how strong hurricane winds can be inland and therefore how to build accordingly.

"Hurricane Charley had the highest sustained winds by far (of the 2004 hurricane season)," he said, explaining that the observations showed 120 -130 mile per hour winds lasting for more than a minute. Hurricane Charley also produced gusts of up to 155 miles per hour.

Several presenters spoke about Hurricane Andrew, still the costliest disaster to ever hit the United States. Michael Brown, director of the Federal Emergency Management Agency (FEMA), said FEMA's reaction time has improved greatly since that storm. The agency had received heavy criticism that they did not respond quickly enough after Andrew.

Brown explained that the help of locally-organized long-term recovery committees greatly improves the recovery process of regions hard-hit by disaster, and he emphasized that long-term recovery should be in the hands of local and state agencies.

"Long-term recovery committees help small towns come back in ways you can't imagine," he said. "(FEMA's) job is not to make people whole, our job is to get them back on their feet.

"I don't think it is the right public policy for FEMA to become the end-all and be-all for disaster victims."

Brown also took time to tout the agency's pre-disaster hazard mitigation grants, as well as to discuss how preparing for disaster should not depend on who or what perpetrates the disaster.

"We have to recognize that the response we do in manmade disasters is similar to natural disasters. It's not the perpetrator I focus on, but rather the response, prevention and preparedness factor."

In terms of Hurricane Andrew's aftermath, some recovery issues remain 13 years later, according to Dr. Betty Morrow, former director of the Laboratory for Social and Behavioral Research at Florida International University's Hurricane Research Center. Morrow did a survey of the South Miami Heights neighborhood directly after Andrew, and then again in 2002 to see what had changed.

"Many families still weren't back to normal," she said. "There was definite uneven recovery."

Morrow showed photos of the neighborhood in 2002. Some houses remained empty, with the residents having picked up and moved away. Other inhabited homes still showed signs of mold and lasting damage. Emotional and mental health issues remained as well. "Ninety percent of the families we spoke with reported moderate or major long-term effects on their families," said Morrow.

After Hurricane Charley, Morrow was invited to do a similar survey of several hard-hit southeast Florida communities. She agreed that the categorization of hurricanes may have helped to produce a false sense of security in that neighborhood. "I heard many families say their house did just fine without shutters, yet they don't realize that this was a very fast-moving hurricane."

She worries that the next time may prove worse for some of the residents who think their homes are indestructible.

The positive aftermath she saw was the timely education provided to residents about how to avoid fraud. Morrow added that the earlier attention paid to children's and other social needs was excellent.

Yet increasing coastal populations will continue to challenge disaster responders, said Dr. Havidan Rodriguez of the University of Delaware Disaster Research Center. Combine that with increasing language barriers and vast economic differences among the population, he added, and the disaster recovery community has its work cut out for it.

"There are groups that are disproportionately affected by disasters," explained Rodriguez. "Language is changing in the U.S., the percentage of female-headed households is increasing, and they are more likely to be below the poverty line. And the number of elderly is increasing in the country. This means an increase in a population with special needs."

Whether or not these coastal populations will have to deal with more yearly hurricanes is uncertain though, said Thomas Knutson. "But the maximum intensities of these storms is likely to increase due to warmer sea surface temperatures," added Knutson, research meteorologist at the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory. The other likely increase in the future is for storm-related precipitation.

"We really don't know what the future holds for change in frequency of tropical cyclones," he explained. "The assessment of tropical cyclone climate change is that there is no clear evidence of long-term trends."

Wind differences across the Atlantic Ocean and increasing sea surface temperatures were major causes of the intense 2004 hurricane season, said some researchers. Some estimates show the U.S. is about ten years into an Atlantic cycle of increased hurricane activity.

Knutson noted the 2004 hurricane season had the average number of named storms, yet more of them made landfall. Knutson also said that the detection of human effects on hurricane intensity will not be likely in the near future.


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