Beginning this weekend, king tides are expected to cause at least some minor flooding from the Mid-Atlantic states through South Florida. King tides are exceptionally high tides that typically arise during a new or full moon and when the moon is at its perigee every 28 days.
The moon reaches perigee, its closest point of approach to the earth, on Friday, Oct. 5, and it hits the new moon phase on Monday, Oct. 8. This results in what is known as a perigean spring tide.
The new moon lines up directly between the earth and the sun, so the sun’s gravitational effect on tides is added to the moon’s gravitational pull. That makes the oceans bulge a bit more than usual and makes high tides higher than normal.
The National Ocean Service says the Mid-Atlantic and southeastern states could see minor tidal flooding in low-lying areas along the coast. The places that have the greatest chance of seeing high tide flooding are Myrtle Beach and Charleston, South Carolina; Fort Pulaski, Georgia; and Fernandina Beach, Florida.
Here a video captured 2 years ago:
Water levels were already running high this week along the southeast U.S. coast because persistent onshore winds have combined with the wave run-up due to Hurricane Leslie’s swells pounding ashore.
If Tropical Storm Michael hits next week, it will have the potential to cause much higher storm surge damage than normal, due to it hitting during the king tides.