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                Understanding Coastal Flooding and Storm Surge

 

What is coastal flooding/storm surge? 

  • Storm Surge is an abnormal rise of water generated by a storm, over and above the predicted astronomical tide. 

  • Storm Tide is the water level produced during a storm due to the combination of storm surge and the astronomical tide. 

  • Astronomical Tide-The twice daily alternating rise and fall of sea level produced by gravitational attraction of the moon and sun. 

  • Inundation is water covering normally dry land. 

Total Water level = Storm surge + Tides + Wave runup/setup + Freshwater Flow

 


 

Factors Affecting Storm Surge: 

  • Central Pressure

  • Intensity (wind speed)

  • Forward speed

  • Size (Radius of Maximum Winds)

  • Angle of Approach

  • Width and Slope of Shelf

  • Local features- concavity of coastlines, bays, rivers, headlands or islands

 

 

Hurricane Storm Surge

NHC Introduction to Storm Surge

 

 

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