Hurricane Harvey Threatens to Bring Dangerous Storm Surge and Flooding to Texas Coast

August 24, 2017 | 6:48 pm
Kristy Dahl
Principal Climate Scientist

UPDATE (August 25, 10:15 PM EST)Hurricane Harvey has become a Category 4 storm with sustained winds of over 130 miles per hour. The storm is due to make landfall near the town of Rockport, Texas, sometime tonight. Affected areas can expect heavy rains, high winds, and, along the coast, storm surge in the hours and days ahead.

The National Hurricane Center has updated the storm’s predicted path over the next few days. It’s now predicted to move inland over Refugio and Goliad Counties, then make a narrow counter-clockwise loop through Karnes and Bee Counties before returning to Refugio County, nearly to the same point at which it’s expected to make landfall. These counties are within the bullseye with predicted rainfall of more than 20 inches.

UPDATE (August 25, 4:15 PM EST): Hurricane Harvey has now been upgraded to a Category 3 storm, with winds of 120 miles per hour. Using Harvey’s predicted storm surge, UCS analysis finds that at least 21 energy facilities along the Texas and Louisiana coasts are exposed to flooding from storm surge alone. High winds and additional flooding due to Harvey’s predicted rainfall could also severely affect the region’s energy facilities.

Map of energy facilities exposed to Hurricane Harvey’s predicted storm surge; Data Sources: NOAA/NHC; U.S. Energy Information Administration. Map and analysis by: Kristina Dahl

The analysis includes five types of energy facilities: power plants, petroleum product terminals, petroleum refineries, natural gas processing plants, and LNG import/export terminals. UCS’s 2015 Lights Out? analysis additionally identified 80 major electric substations outside of leveed areas in Louisiana that could be exposed to storm surge from theoretical storms of Harvey’s strength.

List of energy facilities potentially affected by Hurricane Harvey’s storm surge.

Along the Gulf Coast, some energy facilities fall within leveed areas. NOAA’s storm surge predictions exclude these areas, as modeling surge within leveed areas requires a high degree of confidence in local levee properties and conditions. For that reason, energy facilities within leveed areas, such as around New Orleans, were also excluded from this analysis.

Credit: National Weather Service

UPDATE (August 25, 1:30 PM EST): The National Hurricane Center is reporting that Naval Air Station Corpus Christi is experiencing tropical storm force winds as Hurricane Harvey approaches the Texas coastline. The National Weather service is warning residents of the Middle Texas Coast and barrier islands that “locations may be uninhabitable for weeks or months” as deep, widespread flooding from storm surge and wave action batter homes and structures. Worryingly, they also warn that escape routes and secondary roads may become severely flooded or washed out.

The projected path of Harvey remains about the same as yesterday, with the storm expected to make landfall near Rockport, TX sometime late Friday night or in the early hours of Saturday morning as a Category 3 hurricane. The areas shown in pink below can expect to see impacts from the storm.

Data credit: National Hurricane Center as of Friday August 25, 2017 at 14:16 UTC. Map by Kristina Dahl

The forecast calls for the storm to continue to batter the Texas coast through Wednesday, with the prospect of a prolonged period of drenching rainfall and flooding. With the region’s energy infrastructure at risk, the Energy Information Administration is showing facilities in the storm’s path here.

An analysis by CoreLogic suggests that more than 200,000 homes in Texas are at risk of storm surge damage from Harvey, with a reconstruction cost value of nearly $40 billion.

Residents of several coastal Texas counties have been ordered to evacuate. Despite the fact that the storm’s path is projected to pass within 30 miles of Corpus Christi, the city has not ordered evacuations, but is strongly encouraging residents to leave.

Hurricane Harvey has intensified rapidly off the Texas Coast, and the National Hurricane Center is warning Texas residents that “preparations along the middle Texas coast should be rushed to completion today” because winds may be too strong to do so tomorrow. The storm is expected to make landfall on Friday night, almost precisely 12 years since Hurricane Katrina’s landfall. It would be the first direct hurricane hit in Texas since 2008 and, potentially, the first Category 3 hurricane to make landfall in the U.S. since Hurricane Wilma in 2005.

If you are in Texas or Louisiana, it’s a good time to review hurricane readiness basics.


Residents need to prepare for high winds, heavy rainfall, and storm surge flooding

Harvey is currently southeast of the Texas coast and has wind speeds of over 70 miles per hour. If the storm continues to intensify, becoming a Category 3 hurricane as is currently predicted by the NHC, maximum sustained winds could reach 111-130 miles per hour.

In addition to these extremely dangerous winds, the NHC is predicting that parts of Texas could experience life-threatening flash flooding and up to 30 inches of rain. It’s important to note that this flooding could occur not just along the coast, but inland as well. And, as the map below shows, the area subject to potential flooding extends all the way from southern Texas to the Florida panhandle.

Heavy rain could combine with potentially life-threatening storm surge in coastal areas from Houston to Brownsville. These areas are under storm surge watches or warnings issued by the NWS. These storm surge warnings are an important first for the National Weather Service, as they are the first time NWS has ever issued a public warning specifically for storm surge.

The National Hurricane Center’s latest forecasts suggests that parts of the coast could experience storm surge of more than 9 feet above ground level, which the largest impacts centered southeast of Victoria near the towns of Indianola and Port O’Connor.

The development of this warning system just became operational this year and represents an important collaboration between the National Hurricane Center and NWS. These warnings are based on the latest forecasts and incorporate the uncertainty associated with those forecasts–it’s a huge step forward for national storm preparedness efforts.

Residents can check local tide predictions to get a sense of the timing of a potential amplification of storm surge by high tide.

Potential for storm-related impacts to energy infrastructure

The Gulf Coast encompasses nearly half of the country’s petroleum refining and natural gas processing capacity. UCS research “Stormy Seas, Rising Risks” has shown that Marathon Petroleum’s Texas City refinery and Exxon Mobil’s Baytown refinery are both risk of flooding with a Category 3 hurricane. And much of the central Gulf Coast’s electric grid, as shown in our report “Lights Out?: Storm Surge and Blackout Along the Gulf Coast, and How Clean Energy Can Help,” is exposed to inundation from such a storm. Power outages can affect the ability to safely handle wastewater and provide clean drinking water to communities, as was seen during Superstorm Sandy in 2012.

Juan Parras, Executive Director of Texas Environmental Justice Advocacy Services (TEJAS) and Yvette Arellano, the organization’s Policy and Research Liaison report that they are concerned about leaks and flaring (gas combustion) from the refineries and how they will affect neighborhoods surrounding the refineries.

You can find more information about impacts in our report, “After the Storm: The Hidden Risks of Flooding in a Warming World.” 

An active hurricane season

Back in May, NOAA issued its seasonal hurricane outlook, predicting a 45% chance of an above normal hurricane season with 2-4 major hurricanes and 11-17 named storms.

The season got off to an early start, with Tropical Storms Bret and Cindy occurring simultaneously in the Atlantic before July. Harvey marks the 8th named storm of the season, which stretches from June 1 through November 30th. The season marks a departure from a relatively quiet period with few major storms affecting the U.S. in recent years.

A storm of this magnitude demonstrates the critical role of the federal government

From developing storm surge warning systems to monitoring storm conditions on the ground and via satellite, the federal government plays a critical role in helping states and local communities stay safe ahead of and during the storm. Local emergency preparedness efforts rely on the NHC’s predictions, for example, and they need to have enough lead time to prepare and evacuate residents in harm’s way.

As this storm and its dangers unfold in the coming days, the federal government will again have a strong role to play. The new FEMA administrator, Brock Long, brings a wealth of experience to the job that will be valuable in the days ahead.

But we also need strong support and leadership from the top, and the nation will have its eyes on our president in the days and weeks ahead, as it has in the wake of disasters such as Hurricane Betsy, in 1965, when then-President Lyndon Johnson flew to flood-ravaged New Orleans, entered a crowded shelter and announced “This is your President! I’m here to help you!” or when George W. Bush remained on vacation as Katrina devastated the Gulf Coast.

The Trump administration has taken a number of actions that undercut our nation’s ability to prepare for and respond to natural disasters. At a moment when our country desperately needs unity and leadership from its leaders, may Trump learn from the lessons of his predecessors and ensure that the residents of Texas stay safe now and in the wake of Hurricane Harvey.

Rachel Cleetus, Rachel Licker, and Barbara Briggs contributed advice and reporting to this post.




About the author

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Kristina Dahl is principal climate scientist for the Climate & Energy program at the Union of Concerned Scientists. In her role, she provides scientific direction, strategic thinking, and technical and analytical expertise for the climate team as well as across UCS campaigns and programs. Her research focuses on the impact of climate change, particularly sea level rise and extreme heat, on people and places.