Homeland Security Planning Scenarios

Scenario 10: Natural Disaster - Major Hurricane

Summary

Scenario Overview:

General Description - Hurricanes are intense tropical weather systems consisting of dangerous winds and torrential rains. Hurricanes often spawn tornadoes and can produce a storm surge of ocean water that can be up to 24 feet at its peak and 50 to 100 miles wide. The most destructive companion of hurricanes is the storm surge.

A typical hurricane is 400 miles in diameter and has an average forward speed of 15 miles per hour (mph) in a range of 0 to 60 mph. The average life span of a hurricane is 9 days in a range of less than 1 day to more than 12 days. Hurricanes' highest wind speeds are 20 to 30 miles from the center. Hurricane force winds cover almost 100 miles, and gale-force winds of 40 mph or more may cover 400 miles in diameter. A fully developed hurricane may tower 10 miles into the atmosphere.

A hurricane is categorized by its sustained wind intensity on a Saffir-Simpson Hurricane Scale that is used to estimate the potential for property damage and flooding. "Major" hurricanes are placed in Categories 3, 4, or 5 with sustained wind intensities between 111 mph to greater than 155 mph. The most dangerous potential storm would be a slow-moving Category 5 hurricane, making landfall in a highly populated area.

In this scenario, a Category 5 hurricane hits a Major Metropolitan Area (MMA). Sustained winds are at 160 mph with a storm surge greater than 20 feet above normal. As the storm moves closer to land, massive evacuations are required. Certain low-lying escape routes are inundated by water anywhere from 5 hours before the eye of the hurricane reaches land.

Timeline/Event Dynamics - A tropical storm develops in the Atlantic and is upgraded to a hurricane after 5 days in the open waters. After 4 days, the hurricane has steadied at dangerous Category 4 level on the Safir- Simson Hurricane Scale and models indicate a track that includes a possible landfall along the coast adjacent to the MMA within 2 more days. The hurricane reaches its peak as predicted and makes landfall with a direct hit on the MMA and coastal resort towns. The next day the hurricane moves out. The rain associated with the storm has caused rivers to overflow their banks, and several rivers systems are experiencing record flood levels.

Secondary Hazards/Events - In addition to the massive destruction caused by the hurricane itself, there are also areas within the MMA and scattered inland areas that have sustained severe damage from tornadoes that were generated by the storm. Storm surges and heavy rains cause catastrophic flooding to low lying areas. Rainfall from the hurricane, in combination with earlier storms, causes significant flooding in multiple states along the coast.

Flooded and damaged petrochemical facilities, chemical plants, sewage treatment plants, and other facilities threaten the health of citizens, create a hazardous operating environment, and require cleanup and remediation. An oil tanker is blown off course during the storm and sustains serious damage and leaks oil into the waters adjacent to the MMA.

Key Implications:

The hurricane results in more than 1,000 fatalities, and 5,000 thousand people have sustained injuries requiring professional treatment. Tourists and residents in low-lying areas were ordered to evacuate 48 hours prior to projected landfall. Twenty-four hours prior to predicted landfall massive evacuations were ordered, and evacuation routes have been overwhelmed.

Major portions of the MMA become flooded. Structures in the low-lying areas are inundated when storm surges reach their peak. Many older facilities suffer structural collapse due to the swift influx of water and degradation of the supporting structural base. Newer facilities and structures survive the influx of water, but sustain heavy damage to contents on the lower levels.

Most all shrubbery and trees within the storm's path are damaged or destroyed, generating massive amounts of debris. Debris is also generated from structures destroyed from tornadoes and structures that have been destroyed or damaged by the hurricane. Many structures will need to be demolished.

Service disruptions are numerous. Shelters throughout the region are also filled to capacity. Hundreds of people are trapped and require search and rescue. Until debris is cleared, rescue operations are difficult because much of the area is reachable only by helicopters and boats. Wind and downed trees have damaged nearly all of the electric transmission lines within the MMA. Most communications systems within the impacted area are not functioning due to damage and lack of power.

Thousands are homeless, and all areas are in serious need of drinking water, and food is in short supply and spoiling due to lack of refrigeration. Sewage treatment plants in the region have been flooded and sustained damaged from the storm. Factories, chemical plants, sewage treatment plants and other facilities in the MMA have suffered severe damage. Hundreds of thousands of gallons of extremely hazardous substances have spilled into the floodwaters. There is also gasoline, diesel fuel, and oil leaking from underground storage tanks. A 95,000-ton tanker struck a bridge, breaching the hull of the vessel, which then began to leak oil into waters adjacent to the MMA. All of these issues threaten public health.

Many businesses have experienced damage to buildings and infrastructure as well as lost employees and customers. Military facilities are damaged, and assistance is needed to provide for the military community and to reconstitute the facilities. The 20-foot storm surge has breached and overtopped flood control and hurricane protection works. All transportation routes are damaged to some degree, and the port facility has also been adversely affected. Many hospitals have sustained severe damage and those that are open are overwhelmed. Schools that are not severely damaged are being used as shelters for the disaster victims. Thousands of pets, domesticated animals, and wild animals have been killed or injured, and officials have been overwhelmed with requests for assistance in finding lost pets.

There are severe economic repercussions for the whole state and region. The impact of closing the port ripples through the country. The loss of the petro-chemical supplies could raise prices and increase demand on foreign sources.

Mission Areas Activated:

Prevention/Deterrence/Protection - As the storm approaches, state and local governments are given increasingly accurate forecasts and assessments of possible impacts. Forecasters have difficulty predicting the intensity of the storm prior to landfall, but urge officials to prepare for the worst. State and locals have time to execute evacuation plans.

Emergency Assessment/Diagnosis - Assessment is required for infrastructure, rapid needs, search and rescue, health and medical, and navigation. Remote sensing and modeling help determine the extent of the damages.

Emergency Management/Response - Some of the response actions require include search and rescue operations, mortuary services and victim identification, medical system support, debris clearance and management, temporary emergency power, transportation infrastructure support, infrastructure restoration, and temporary roofing.

Incident/Hazard Mitigation - Support is required to coordinate the development of plans to execute mitigation efforts that lessen the effects of future disasters. This includes studies to assess flood and coastal erosion and intergovernmental plans to mitigate future damages.

Public Protection - Measures need to be taken to control vectors that may thrive in the areas after a catastrophic hurricane. Support will be required to maintain law and order and to protect private property. Support will be required to test and analyze health and safety hazards and implement measures to protect the public.

Victim Care - Care must include medical assistance; shelter and temporary housing assistance; emergency food, water, and ice provision; and sanitary facility provision.

Investigation/Apprehension - Not applicable (natural disaster).

Recovery/Remediation - Hazardous materials will contaminate many areas, and decontamination and site restoration will be a major challenge.