Sandia LabNews

Team gears up for hurricane season


NISAC TEAM — A NISAC team of infrastructure modelers and analysts works on providing a crisis response to the Department of Homeland Security. When NISAC is activated, such teams provide quick analyses to DHS for national events such as hurricanes.  (Photo courtesy of NISAC)

A Sandia team is gearing up for hurricane season, readying analyses to help people in the eye of a storm.

The Department of Homeland Security’s National Infrastructure Simulation and Analysis Center (NISAC), jointly housed at Sandia and Los Alamos national laboratories, studies the interdependency and vulnerability of critical infrastructure and the consequences of having systems disrupted by disasters, including hurricanes.

Hurricane season began June 1 and runs through Nov. 30. It generally peaks in August and September, notwithstanding Superstorm Sandy’s appearance late last October.

NISAC has two jobs relating to hurricanes: conducting annual “hurricane swath” analyses of probable impacts on the Gulf Coast and East

Coast and providing quick analyses of crisis response in the face of an imminent hurricane threat to the United States.

Analyses allow preliminary look at storm

A swath analysis looks at how a hurricane might interrupt electricity or water service and at impacts specific to an area, such as petroleum and petrochemical industries in Houston or financial services in New York City. It also looks at such things as the economic impact of the storm or how it could upset food deliveries.

Federal officials pull swath analyses off the shelf when a hurricane seems likely to hit a particular place. They used the New Orleans report a few days before Hurricane Isaac headed toward that city last August.

“While it was too far out for us to do our analysis, they could use the report as a first cut,” says Dan Pless (6924), NISAC program lead at Sandia.

NISAC’s portfolio includes a dozen swath analyses updated every few years, two cities at a time. A team coordinated by Mark Pepple (6632), NISAC fast response lead, this year updated reports for Houston and Corpus Christi, Texas; last year the work focused on Miami and Tampa. Updates keep information from becoming too stale, Dan says.

NISAC decided what to put into the original analyses, but is working on updates with state and local officials and Department of Homeland Security (DHS) agencies, including the Federal Emergency Management Agency (FEMA).

Reports analyze ‘reasonable bad scenario’

Each report uses a “reasonable bad scenario” that would be possible in the particular area, with local officials deciding what scenario would be most useful for disaster planning, say Dan and Mark. For example, a Category 5 hurricane isn’t likely in New York City because colder waters dampen hurricane strength, but a Category 3 is within reason.

“These storms form in the Caribbean, they form in the Gulf. They can get quite strong down there,” Dan says. “They don’t form in the North Atlantic. They have to travel there.”

The analyses — also useful in other natural disasters — consider impacts to the infrastructure, the population, and the economy, Dan says.

“We look at where power outages are likely,” he says. “For Houston, it would examine the possible national impact on petroleum supplies and whether we should worry about that.”

They look at so-called food deserts: urban areas where food deliveries might be interrupted, he says.

NISAC also has found that some local officials want more demographic information. Officials in Florida, with its high retiree population, want to know where the elderly are concentrated, Dan says.

The most difficult part of an analysis is defining a scenario because every place is different and a wide range of agencies must reach consensus, he says.

Team activated for big hurricanes

Once NISAC is activated, the team focuses on exactly what’s in the storm’s projected path.

 “Anytime a hurricane is going to make landfall in the US we’re busy at some level. If it’s going to be a Category 3 or higher you can pretty much figure we’re going to go to full activation,” Dan says. The decision whether to activate and to what degree comes from NISAC’s program manager at the DHS, the Homeland Infrastructure Threat and Risk Analysis Center, known as HITRAC, part of the Office of Infrastructure Protection.

Mark helps lead NISAC’s crisis response. When federal officials activate a team, he coordinates with HITRAC and Sandia’s partners at Los Alamos, which has its own team doing analyses. The labs collaborate. For example, Los Alamos models and analyzes the impacts to electricity and metropolitan water systems, and Sandia uses those results to look at impacts to energy such as petroleum and natural gas or sectors such as transportation and banking. 

He’s also responsible for getting Sandia’s team together, not just pulling in people, but identifying what expertise or simulation tools are needed. While a crisis response team always needs at least one economist to assess economic impact, a hurricane in Houston would require more analyses of the petrochemical sector than a hurricane in North Carolina, where agriculture could be a larger concern.

NISAC and HITRAC collaborate on how much time the team has before it locks in a prediction of the hurricane’s track toward land. The National Oceanic and Atmospheric Administration issues regular landfall projections. At some point, NISAC has to lock in a storm track, or prediction, on which to base its analyses.

Dan says the amount of time for analysis is shrinking. NISAC had 48 hours for Hurricane Gustav, which hit the South in late August and early September 2008.

“They said that’s too much time, the track can change too much in that time,” Dan says.

The team had 24 hours to do its analysis for Hurricane Ike, which hit the Texas, Louisiana, and Mississippi coasts in September 2008. By the time Irene hit the East Coast in August 2011, the deadline had dropped to 12 hours. “We’re roughly around 10 to 11 hours at this point,” Dan says.

The team provides similar information as for a swath analysis, with less detail but using the hurricane’s strength and what’s in its path. While the report generally focuses on the projected track, sometimes the team adds a caveat that damage could be worse if the storm changes path.

Questions spike when hurricane hits

The team also responds to a flurry of questions from DHS just before landfall. For Ike, Dan says, officials wanted to know which large Houston-area water treatment plants were most likely to lose power and could use one of three available FEMA generators.

For Sandy, NISAC’s report identified subways in the storm surge zone and did some power outage modeling.

Questions usually spike after a hurricane hits. That was particularly true for Sandy.

“You had this massive power outage and they were wondering, ‘OK, we have these cell towers and a lot of them have diesel generators for backup. Those last 48 to 72 hours and the power isn’t coming back in 48 to 72 hours. How do we prioritize that? Few of the gas stations have fuel, what’s going on? Is it that they don’t have power or because eight of the nine fuel delivery terminals in New Jersey were down?’” Dan recalls.

Sandy reversed the normal workload.

“Usually we have a lot heavier workload going into the hurricane before landfall and generally have tired people and a lighter workload afterward. On Sandy, we worked the opposite. We had a relatively light workload going in and then it got really busy,” Dan says. “That was because it was that weird perfect storm.”