Hurricane Season’s Start Brings New Storm Surge Maps

When Hurricane Sandy struck the Northeast, it was not the storm’s winds but the massive pile of water those winds pushed in front of the storm that wreaked the most havoc, inundating coastal areas in 3 to 9 feet of water, causing billions in damages, and leaving dozens dead.  In general, this storm surge poses a far greater threat to lives and property than winds when hurricanes and tropical storms hit.

It’s with this in mind that the National Hurricane Center (NHC) has developed an experimental system that maps the projected storm surge in areas under threat from tropical cyclones — just in time for this hurricane season, which began on Sunday, June 1.

Sandy was no different than most other tropical cyclones, the generic term for hurricanes and typhoons, with the major proportion of its damage caused by storm surge.  In the 50-year period from 1963 to 2012, storm surge accounted for nearly half of all tropical cyclone deaths in the U.S., according to a recent study in the Bulletin of the American Meteorological Society.  That’s far more than the 8 percent the study attributed to the high winds many assume to be the biggest danger in a hurricane.  Yet wind speed continues to be the main measure of a cyclone’s strength, determining when a tropical storm becomes a hurricane and what “category” ranking a hurricane receives.

It’s this unappreciated threat from storm surge that prompted the NHC to begin issuing experimental storm surge flooding maps for all tropical cyclones that threaten U.S. coasts starting with the 2014 hurricane season.  The maps will show how high a particular storm’s surge is expected to get in different areas and how far inland it could go.

“This is a really desperately needed update,” said Jamie Rhome, a storm surge specialist with the NHC who is heading the mapping effort.

Adding to the need for such a warning mechanism is the fact that the population along coastal areas has been rising, putting more people in harm’s way.  And rising sea levels — the result of the ocean warming and ice melting due in part to warming global temperatures — are increasing the storm surge threat.  Some research has also suggested that Atlantic basin storm could become more intense, if less frequent, which could effect the level of storm surge coastal communities experience.

Hurricane Season’s Start Brings New Storm Surge Maps