Miami broke an all-time record for high tide floods in 2019, NOAA says
High tide flood days, the ones where streets and parks get swamped with saltwater despite sunny skies, are becoming more common in Miami. Last year, Miami experienced more of them than ever before.
NOAA predicted the Virginia Key tidal gauge would see one to three high tide flood days in 2019. It recorded nine.
William Sweet, an oceanographer at NOAA’s Center for Operational Oceanographic Products and Services, said on a press call Tuesday that number is due in part to Hurricane Dorian, which hovered off the coast for days in September, as well as sea level rise driven by climate change.
“When sea levels are a foot higher than normal, these garden variety events cause flooding in the streets,” he said. “Unfortunately, it’s the new normal.”
In a newly released report, NOAA found that Miami’s Virginia Key was one of 19 flood gauges across the country that broke or tied their record in 2019. Another Florida location, Cedar Key, also broke its record with 11 high tide flood days. However, the median high tide flood days for all 98 tidal gauges surveyed didn’t break a record like it did last year.
Nicole LeBoeuf, the acting director of NOAA’s National Ocean Service, said high tide flooding is accelerating at 75 percent of the tide gauges surveyed on the East and Gulf Coasts.
She pointed to Corpus Christi, Texas, which saw an average of two high tide flood days in 2000 and saw 18 in 2019.
“Damaging floods that decades ago only happened during a storm now happen regularly,” she said. ”These conditions are changing and not just in a few locations.”
In Miami, the nine high tide flood days recorded in 2019 are a steep jump from 2018, where by NOAA’s standards the area saw zero high tide floods.
Local scientists reported the 2019 king tides, the extra high annual tides that usually occur in the fall, were stronger than those of 2018, but that doesn’t account for the total difference between the annual numbers.
To calculate high tide flood days, NOAA relies on a national standard for flooding that levels out the highs and lows of places like South Florida, which is prone to flooding.
“We really would rather make more of a regional, national assessment...more of an apples to apples comparison,” Sweet said. “As a result, the flood frequencies have gone down in certain areas.”
Research shows places like Miami and Texas’ Gulf Coast experience life-altering levels of flooding before water levels rise to NOAA’s official standard. For instance, NOAA’s official standard for a minor flood is 1.3 feet in Miami, but at just one foot, residents often take to Twitter to post pictures of flooded roads and soggy yards.
NOAA predicts that this season will bring three to six high tide flood days to Miami. By 2050, the organization predicts sea rise could spike that range to 10 to 55 days. South Florida is planning on seeing a little over two feet of sea level rise by 2060, but that could decrease if humans stop burning so much fossil fuel.
Gregory Dusek, the chief scientist for NOAA’s Center for Operational Oceanographic Products and Services, noted that these predictions are based on current infrastructure, which also has the possibility to change.
Cities across South Florida are doing just that, fighting rising tides with higher roads and buildings, more pumps and landscaping designed to absorb floodwater and deflect waves.
This story was originally published July 14, 2020 at 4:34 PM with the headline "Miami broke an all-time record for high tide floods in 2019, NOAA says."
