It’s that time of year again: King tides, or larger than normal tides, will hit South Florida in the coming days, potentially causing street flooding in low-lying coastal areas.
Traffic, too, could become an issue, as the flooding tides coincide with rush hour.
The tides will recur periodically through early December, and some will be stronger than others.
According to the National Oceanographic and Atmospheric Administration and various local municipalities, king tides will occur along South Florida’s coast on the following dates:
— Sept. 20 to 23, due to a new moon Sept. 21.
— Oct. 4 to 12, due to full moon Oct. 6.
— Oct. 18 to 24, due to new moon Oct. 21.
— Nov. 1 to 10, due to full moon on Nov. 5.
— Nov. 18 to 20, due to new moon Nov. 20.
— Dec. 2 to 7, due to full moon Dec. 4.
Most high tides during the full and new moons happen twice a day, in the morning and early evening, as the moon is aligned with the sun. Unfortunately, this also aligns with rush hour. Tides get an hour or so later each day as the month progresses.
Such tides often result in coastal sunny-day flooding. The South Florida Water Management District warns that saltwater is corrosive, and can damage cars that drive through it or park in it.
“King tide” is actually a colloquial term for the large tides created when the gravitational force of the sun and moon reinforce one another, according to NOAA. This occurs when the sun and moon align at the same time the moon’s orbit swings closer to earth than normal.
Sea-level rise has exacerbated king tides, according to the water management district.
Atmospheric researcher Brian McNoldy, of the University of Miami’s Rosenstiel School of Marine, Atmospheric and Marine Science, has been tracking sea-level rise over time. His analysis of NOAA data indicates water levels at Virginia Key have risen about 6 inches since 1995.
Strong onshore winds can enhance high tides as well.
Not all king tides are created equal, with some flooding higher than others.
The highest tides of this season should happen near the full moon on Oct. 8, according to the water management district. The next full moon, on Nov. 5, will be nearly as high.
The high tides around the new moons of Sept. 21 and Oct. 21 will be higher than normal, but not quite as powerful as those on the full moons.
