Dear Tom,
What is hurricane storm surge?
Donna Spanko
Dear Donna,
Storm surge is a rise in the level of the sea when a tropical cyclone makes landfall, and it can devastate low-lying coastal areas.
Surges vary from 1-4 feet in weak tropical storms to more than 20 feet in Category 3 or greater hurricanes.
Surge results from several factors: the winds of the storm pushing water onshore; reduced air pressure that accompanies a hurricane (the ocean level rises about one foot for every inch the air pressure falls below 30 inches of mercury); the topography of the ocean floor (a gradual rather than abrupt upward slope of the shoreward floor creates greater surge); the shape of the coastline (bays trap water and increase surge); and the timing of astronomic tides.
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Tom Skilling is chief meteorologist at WGN-TV. His forecasts can be seen Monday through Friday on WGN-TV News at noon and 9 p.m.
WGN-TV meteorologists Steve Kahn, Richard Koeneman and Paul Dailey plus weather producer Bill Snyder contribute to this page.
