King tides could make flooding from Tropical Storm Dorian worse. Storm surge is biggest factor.

With Tropical Storm Dorian churning toward the east coast of Florida, residents can expect a very wet and windy weekend, but another phenomenon could compound the watery hazards — king tides began Monday and are expected to continue through next Tuesday, Sept. 3.

King tides occur when the sun and moon are in such a position that the resulting tides are larger than normal, when the moon is closest to the Earth in its orbit and the Earth is close to the Sun in its own orbit. When that happens, the tides get higher and have caused flooding in some South Florida cities even on sunny days.

...

The combination of heavy rainfall and king tides could mean flooding events somewhat greater than are typical with a tropical storm, according to Jamie Rhome, storm surge specialist with the National Hurricane Center. But Rhome stressed that there are other more important factors in determining flood dangers for our region.

“If you look at the magnitude of water rise, where the hurricane goes and how powerful it is, [that] is so much more important,” he said. “With water levels elevated, it would increase the potential for coastal flooding for any hurricane that could make landfall here.”