Texas' hurricane history holds important information that can help decision-makers working in urban planning, disaster management and mitigation, and the stewardship of natural resources, according to researchers at the Houston Advanced Research Center (HARC), Texas A&M University-Galveston and the National Oceanic and Atmospheric Administration.

Among key findings in a recently published study by these experts:

Since 1851, the Upper Texas Coast has been hit by more tropical storms and hurricanes than the Lower Texas Coast.

Most of the Upper Coast storms originated in the Gulf of Mexico, rather than in the Atlantic.

Gulf storms that hit Texas "may form very early in the hurricane season and can possess unique threats to coastal ecosystems, infrastructure, and people."

The study's authors included HARC President Robert Harriss. They recommended that officials preparing hurricane emergency plans and public education strategies should place special emphasis on Gulf storms "that can develop and intensify rapidly with landfall in a matter of hours to a few days."

The authors noted that the Upper Coast's experience with Hurricane Rita in 2005 demonstrated that evacuation of heavily populated areas can take longer than the warning period allows.

Because increasing population and development are making such large-scale evacuations harder to carry out, "alternative approaches to protect life and property must be considered," they advised.

Emergency planners might consider "vertical evacuations" - sheltering upstairs in hurricane-resistant buildings - at times that the traditional, "horizontal" movement of large numbers of people away from threatened areas becomes "dangerous or impossible," they wrote.

The researchers also recommended consideration of projects to construct coastal barriers with floodgates to prevent storm surges from rushing into bays and estuaries.

The Houston region's booming population provides an important motivation to decide on the most effective ways to withstand and mitigate hurricane impacts, Harriss said.

"The Houston-Galveston Area Council's forecast that our region will be home to 8.8 million people by 2035 suggests that vulnerability to hurricanes will grow significantly," he said. "Serious attention to best practices for keeping people and critical infrastructure out of harm's way are urgently needed."

Another study author, William Merrell of Texas A&M-Galveston, stressed the paper’s sharp geographic focus and unexpected results.

"This paper was written from a Texas perspective and especially for Texans who are affected by hurricanes and tropical storms," said Merrell, Professor and George P. Mitchell Chair in Marine Science.

"The results are surprising, especially for the upper Texas coast, where storms that form in the Gulf outnumber Atlantic hurricanes," he added. "These Gulf-generated storms have two nasty characteristics - they often speed up as they approach land and they often intensify shortly before hitting."

The researchers also found that a major hurricane - Category 3 or 4 - hits the upper coast about every 15 years, Merrell said.

"These facts  have significant impact on how we plan evacuations, response and recovery in the region, as well as in planning our coastal defenses."

The researchers set out to make sure their paper would be a user-friendly contribution to the evolving public dialogue about hurricane preparedness in Texas.

They noted that "most of the published materials on hurricanes are too demanding of time or technical expertise to meet the requirements of being 'usable science' that might inform public planning or private investment in coastal counties and cities."

To make their work more broadly accessible, they included "visual representations of hurricane histories based on state-of the-art data and robust basic statistics, combined with a relatively brief explanatory text that can be understood by a broad range of interested citizens."

The first part of the paper provides a comprehensive climatology of Texas hurricanes from 1851 through 2006. The second part offers historical case studies of hurricanes that rapidly formed before making landfall on the Texas coast.

In terms of climatology, they concluded: "The distribution of all tropical storms and major hurricanes hitting Texas shows a peak in August and September. However, Gulf-originated storms and major hurricanes often form early in the hurricane season and actually peak in June."

Monthly distribution of major Texas hurricanes 1851-2006

Monthly distribution of Texas storms formed in the Gulf of Mexico 1851-2006

The authors explained the significance of their case studies of four 20th century hurricanes:

 "All too often, hurricane planning is primarily informed by the most recent serious event, or by generic scenarios that do not reflect important regional hurricane characteristics that are 'knowable' from historic records."

The case studies, they said, make a number of things clear that should be considered in emergency planning:

Major Gulf-forming hurricanes can intensify quickly (as happened with a 1932 storm).

They can move quickly as their strength intensifies near land (Audrey, 1957).

They can change direction near the coast (a 1945 hurricane).

They can become stronger just before landfall (the 1932 storm and 1983's Alicia).

The researchers noted that Hurricane Humberto, which occurred soon after the 1851-2006 period covered by their analysis, also gave virtually no warning before its September 2007 formation in the Gulf. Humberto "actually achieved hurricane status while over land on the Bolivar Peninsula," they added.

"Origin, Distribution, and Timing of Texas Hurricanes: 1851-2006" appeared in the November 2009 edition of the journal Natural Hazards Review, published by the American Society of Civil Engineers. The two other authors were Tanveerul Islam, Research Associate at the NOAA Environmental Cooperative Science Center at Florida A&M University, and William Seitz, Professor of Marine Science and Associate Vice-President at Texas A&M-Galveston.