Gustav bears down on U.S. East Coast: the Hurricane Scenario: Gustav, an intense Cat 4 storm, wreaks supreme havoc upon the Eastern Seaboard, leaving a trail of losses from Key West to Cape Cod

Risk & Insurance, April 15, 2004 by Auguste Boissonnade

The Hypothetical Scenario:

Early in the fall, the National Hurricane Center satellites identify a tropical depression in the middle of the Atlantic Ocean, moving west from the coast of West Africa. As the depression gains strength over warm water, it grows into a tropical storm. NHC calls the storm Gustav. It is the seventh tropical cyclone to emerge that year in the North Atlantic basin. NHC experts monitor it over a week as it develops into an intense hurricane that sends a glancing blow at Barbuda before heading toward the Bahamas.

Projections show that it is likely to make landfall along the east coast of Florida in Palm Beach County. With sustained winds of 145 mph, Gustav is a Saffir-Simpson Category Four storm. With landfall two days away, a hurricane warning is issued along the southeastern coast of Florida from north of Miami to Cape Canaveral. The tropical storm warning covers a broader area, from Key West to Jacksonville.

As the hurricane nears the coast, do-it-yourself and hardware stores sell out of materials and tools as residents and building owners install shutters or attempt to board-up windows. Tens of thousands of people evacuate coastal communities in the likely path of the hurricane and move inland.

As time passes, Palm Beach County and its surroundings are almost deserted. Only emergency personnel remain; a few stubborn residents and journalists are left behind. Risk managers and emergency officials are preparing for the worst. The Nuclear Regulatory Commission's Region II office in Atlanta implements its hurricane response procedure and shuts down a plant in St. Lucie. Other plants are on high alert. Utility companies activate their emergency plans.

Forecasters use reconnaissance planes, eyewitness accounts, satellite imagery and an ensemble of atmospheric models to forecast where the storm will make landfall. The latest forecasts suggest that the storm will move inland at approximately the same location as the "Great Lake Okeechobee" hurricane of September 1928, a Category Four hurricane that hit the coast near Palm Beach with sustained winds of 128 mph. At the time of Gustav's landfall, maximum gusts of 160 mph are observed in some coastal areas within the eye wall. Intense rain is reported and several tornadoes have been spotted. Gusts of 80 to 90 mph are reported in the Miami metropolitan area, about 60 miles south of where the hurricane came ashore. Heavy surf and surge affect the coastline over more than a hundred miles. Surge heights reach 15 feet over a 20-mile coastal stretch near Juno Beach, about 25 miles north of where Gustav made landfall. Florida's governor asks the President to declare Florida a major disaster area.

Once on land, Gustav weakens and begins to swing toward the north and northeast, ensuring that the highest winds remain over the heavily populated coastal communities. Gustav is quickly downgraded. Seven hours after landfall it is a tropical storm generating gusts of 80 to 90 mph at Cape Canaveral and 50 to 60 mph by the time it reaches Georgia, whereupon the storm moves back offshore. Its path is similar to the 1928 storm but as it remains closer to the coast, the high winds affect more of the coastal areas.

In the regular NHC forecasts, tropical warnings are now extended along the entire Eastern Seaboard, as the storm moves up the coast toward the Northeast.

With Gustav once again over water for about six hours, it strengthens and speeds up as it skims the coast before making landfall in South Carolina with sustained winds of 60 to 70 mph.

The storm moves north and becomes an "extra-tropical" storm as it moves along the Eastern sea board with gusts reaching 50 to 60 mph in coastal areas as far herd1 as Massachusetts over the next two days.

The storm left an impact on much of Florida's eastern coast. The most damage took place along 100 miles of coastline, between Pompano Beach and Port St Lucie. The most severe damage is reported in coastal communities. In some areas the coastal landscape has changed completely. Beach houses have been uprooted from their foundations and debris is floating in the streets, swept in by heavy surf. Many older buildings that were not built in accordance with current state and local building codes are destroyed or heavily damaged. Resorts along the coast suffer extensive damage. Several lose their beach access.

Gustav affects more than seven million Florida residents. More than 1,000 coastal structures have lost 50 percent of their market value, victims of pounding surf. Thousands of other properties suffer minor to moderate damage. In all, about one million homes, condos and apartment buildings are affected by the storm, 400,000 of them severely. In addition, 200,000 commercial properties are damaged by the storm.

POWER FAILURES

Power outages are reported over large areas of Florida where high winds topple trees and branches knock out transmission and distribution lines. More than three million customers are without power for as long as three days. Some residents have to wait several weeks before power is restored. Businesses suffer the brunt of these power outages as inventory perishes or is simply destroyed. Fortunately, only a few hospitals and fire stations suffer extensive damage.