Get ready for big swell of king tides

Put on your flip flops and hike up those pants, South Florida.

What could be the worst king tide flooding of the year may start as early as next week. That means the local “sunny day flooding,” periods when water submerges low-lying areas even though there’s no rain in sight, is about to return.

The worst king tide flooding of the year is forecast to coincide with next week’s new moon, but the floods return in three weeks with the full moon. During the October new moon (Oct. 6) and full moon (Oct. 20), the moon is closest to Earth.

“The effects on the tides is it’s going to be a little above average,” said National Weather Service meteorologist Barry Baxter.

King tides, which cause rising seawater to overtake seawalls and flood city streets, began last month and continue through December. Last month’s king tide effects were minimal. The flooding will be noticeable this month.

“We’re going into the peak of it,” Baxter said. “And the peak should be later this month into early next month.”

South Florida is catching a break of sorts on next week’s king tides because there’s no tropical system forecast to make the water level even higher in the region.

“The only way we can get more of it if is we had a tropical system at the same time,” Baxter said. “That’s the only thing that could cause it to be more aggravating.”

Climate change and the rising sea level are thought to have made recent king tide levels even higher.

Daily high tides can rise by a foot or more during king tide, according to the National Oceanic and Atmospheric Administration. It’s a phenomenon caused when Earth’s northern hemisphere is closest to the sun, and the sun and moon align to create gravitational pull which brings about higher tides than normal.

Robert Molleda, warning coordination meteorologist for the National Weather Service, said there’s been a recent trend toward king tide flooding in areas previously considered safe, specifically areas near canals that drain into the Intracoastal Waterway.

“With more flooding events during king tide due largely to sea level rise, areas that people may not think are susceptible to these events are seeing flooding,” he wrote. “For example, areas in the mainland in proximity to canals that lead to the Intracoastal Waterway.

“King tides alone [without contribution from wind and other effects] rarely cause flooding along the beachfront due to the dunes providing a buffer to adjacent land areas. However, you don’t have that same buffer along the Intracoastal Waterway and along canals that lead into it.”

The city of Fort Lauderdale said Nov. 18 and 19 could also be dates to watch for street flooding because of the full moon.

The final sets of king tides in 2021 are expected Nov. 3-9 and Dec. 2-7.