Parts of South Carolina experienced some of the highest king tides of the year along the coast this past weekend. The National Weather Service in Charleston said some of the flooding ranked among the top 10 king tide flooding events since records began. The South Carolina Department of Health and Environmental Control predicted six weeks of above average tides this year which can cause significant flooding especially when combined with high on-shore winds.
King Tide, Charleston pic.twitter.com/H2JwGYMHTs
— Seton Tucker (@SetonTucker) November 16, 2024
The NWS says king tides are always high in this region during the Fall months. But the king tides last weekend were especially notable. For example, on November 16th, the MMLW (Mean of Lower Low Water) high tide in Charleston was 8.25 ft. That was the 21st highest on record.
There were additionally higher than normal tides on November 14th at 8.08 feet. Major flooding begins in Charleston at 8. 0 ft.
In Georgia, Fort Pulaski’s MLLW high tide of 10.25 ft on November 14th was the 9th highest on record and on November 16th it was 10.17 ft which was the 13th highest on record. Moderate flooding begins at 10.0 ft at Fort Pulaski with major flooding at 10.5 ft.
Significant King Tide flooding in the area this morning. This is the scene in Garden City. Coastal flooding begins when tide level reach 7 feet. We peaked at 8.2 feet this morning with similar predictions for Sunday morning. 📸 Ryan Swaim #SCwx @wmbfnews @NWSWilmingtonNC pic.twitter.com/EhJ4LqlUhz
— Jamie Arnold WMBF (@jamiearnoldWMBF) November 16, 2024
So just what exactly is a King tide? Every Spring and Fall the astronomical phenomena called “ king tide” rolls along our eastern shores . The term King Tide is a non-scientific term often used to describe exceptionally high tides. A king tide occurs when a new or full moon coincides with the moon’s perigee which is a point around its month-long orbit when it’s closest to the Earth. The combined gravitational pull of these events causes oceans to swell higher than usual in coastal areas.
King tides occur about 6 times a year. Higher than normal tides typically occur during a new or full moon and when the Moon is at perigee, or during specific seasons around the country. The last king tide of this year was November 14 – 18. But the king tides in September and October were also notable.
King Tides impacts can vary considerably. King tides can bring coastal erosion, flooding of low-lying areas, and road closures which may disrupt normal daily routines. The NWS will issue notifications when the water levels are expected above 6.6 above the mean lower low water ( MLLW).
For more information on the frequency of tidal flooding, see NOAA’s latest State of U.S. High Tide Flooding report.