Map This: National Weather Service Unfurls New Storm Surge Maps As Hurricane Season Begins
Hurricane season began yesterday and runs through the end of November. New this year for the season are storm surge maps from the National Weather Service (NWS) to underscore the danger that a surge poses during a severe storm. Storm surge is an abnormal rise of water generated by a storm, over and above the predicted tide levels, according to the NWS. “Most people see wind as the key threat in a tropical storm or hurricane, but surge can be far more deadly,” said Dennis Feltgen, a spokesman for the NWS.
The new, color-coded maps will be updated every six hours during storms that pose a surge risk along the Gulf and Atlantic Coasts. The maps highlight:
- Geographical areas where inundation from storm surge could occur
- How high above ground the water could reach in those areas
- Inundation levels that have a 10 percent chance of being exceeded
Maps will be available 45 minutes to an hour after each new advisory, to give cartographers time to plot their points.
The new maps are experimental for two years. The NWS will be collecting and reviewing public comments, and then afterward decide whether the maps will become a permanent product. Even if they don’t, say public health experts, the model maps are important right now in order to educate the public about the threat posed by a surge—even at fairly low heights.
For example, six inches of water can knock over an adult and two feet of water is all that’s needed to carry an SUV, according to the data from the NWS.
The NWS’ Feltgen said Hurricane Sandy is an important example to share when explaining storm surge because of the damage that storm’s surge did to inland communities. For instance, the surge knocked out power to many financial firms on Wall Street, which were then powered by generators as repairs went on for months after the storm. And many residents of high rise apartment buildings in Manhattan and other parts of New York City were stranded or limited to stairs until the electricity was fixed and elevators could run.
Other storm surge facts:
- More than half of the nation's economic productivity is located within coastal zones
- 72 percent of ports, 27 percent of major roads and 9 percent of rail lines within the Gulf Coast region are at or below 4 ft. elevation.
- A storm surge of 23 feet has the ability to inundate 67 percent of interstates, 57 percent of arterials, almost half of rail miles, 29 airports and virtually all ports in the Gulf Coast area.
>>Bonus Link: The National Weather Service has a fact site on storm surge, including photos of the havoc wreaked by surge episodes.