Additional Hurricane Hazards and Preparedness Topics
Along the coast, storm surge is often the greatest threat to life and property from a hurricane. In the past, large death tolls have resulted from the rise of the ocean associated with many of the major hurricanes that have made landfall. Hurricane Katrina (2005) is a prime example of the damage and devastation that can be caused by surge. At least 1500 persons lost their lives during Katrina and many of those deaths occurred directly, or indirectly, as a result of storm surge.
Before and after Hurricane Ike on the Bolivar Peninsula, TX, September 2008/USGS
Storm Surge vs. Storm Tide
Storm surge is an abnormal rise of water generated by a storm, over and above the predicted astronomical tides. Storm surge should not be confused with storm tide, which is defined as the water level rise due to the combination of storm surge and the astronomical tide. This rise in water level can cause extreme flooding in coastal areas particularly when storm surge coincides with normal high tide, resulting in storm tides reaching up to 20 feet or more in some cases.
To determine if your home lies within a Storm Surge Zone use the Suffolk County Storm Surge Zone and Shelter Locator Mapping Tool. Click here to go to the Suffolk County Storm Surge Zone and Shelter Locator Mapping Tool.
STORM TIDE is the water level rise during a storm due to the combination of storm surge and the astronomical tide. For example, if a hurricane moves ashore at a high tide of 2 feet, a 15 foot surge would be added to the high tide, creating a storm tide of 17 feet. The combination of high winds and storm tide topped with battering waves can be deadly and cause tremendous property damage along an area of coastline hundreds of miles wide. The destructive power of storm surge and large battering waves can result in loss of life, buildings destroyed, beach and dune erosion and road and bridge damage along the coast. Storm surge can travel several miles inland. In estuaries and bayous, salt water intrusion endangers public health and the environment.
Historical Storm Tide Events:
- 1900: Galveston, TX, hurricane, resulted in more than 8,000 deaths, most by storm tide.
- 1969: Hurricane Camille produced a 24-foot storm tide in Mississippi.
- 1989: Hurricane Hugo generated a 20-foot storm tide in South Carolina.
- 1992: Hurricane Iniki produced a 6-foot storm tide on the island of Kauai in Hawaii.
- 2005: Hurricane Katrina generated a 27-foot storm tide in Mississippi.
- 2008: Hurricane Ike produced a 20-foot storm tide in Texas.
Factors Impacting Surge
Storm surge is produced by water being pushed toward the shore by the force of the winds moving cyclonically around the storm. The impact on surge of the low pressure associated with intense storms is minimal in comparison to the water being forced toward the shore by the wind.
Wind and Pressure Components of Hurricane Storm Surge
The maximum potential storm surge for a particular location depends on a number of different factors. Storm surge is a very complex phenomenon because it is sensitive to the slightest changes in storm intensity, forward speed, size (radius of maximum winds-RMW), angle of approach to the coast, central pressure (minimal contribution in comparison to the wind), and the shape and characteristics of coastal features such as bays and estuaries.
Surge Vulnerability Facts
Visit the National Hurricane Center Storm Surge Web Page.
- From 1990-2008, population density increased by 32% in Gulf coastal counties, 17% in Atlantic coastal counties, and 16% in Hawaii (U.S. Census Bureau 2010)
- Much of the United States' densely populated Atlantic and Gulf Coast coastlines lie less than 10 feet above mean sea level
- Over half of the Nation's economic productivity is located within coastal zones
- 72% of ports, 27% of major roads, and 9% of rail lines within the Gulf Coast region are at or below 4 ft elevation (CCSP, SAP 4-7)
- A storm surge of 23 ft has the ability to inundate 67% of interstates, 57% of arterials, almost half of rail miles, 29 airports, and virtually all ports in the Gulf Coast area (CCSP SAP 4-7)
Additional Huricane Preparedness Topics
Content provided by the National Weather Service