Clearwater Beach is projected to experience high tide flooding an average of 73 days per year by 2050. That’s according to a new NOAA report released Tuesday titled “2023 Annual High Tide Flooding Outlook.”
The two Tampa Bay area cities mentioned in the report, Clearwater Beach and St Petersburg, are projected to have among the most flood days of any coastal cities in Florida by mid-century. The projected increase in flooding is due to sea level rise.
Over the past few years, both cities have averaged just a few high tide flood days per year, but by 2050, that number is expected to average 68 in St. Petersburg — a 20-fold increase.
High tide flooding is defined as overflow of water that typically covers dry coastal land during high tide. It happens when water levels reach anywhere from 1 to 2 feet above the daily average high tide.
This type of flooding is also known as sunny-day flooding because it does not have to be storming outside to force the water onto land. It most often occurs when there is an excessively high tide due to a super moon and strong onshore winds or large swells.
It is often a nuisance, flooding low-lying intersections and areas that typically flood. But it can be made worse if the high tide coincides with a strong storm.
But as sea level continues to rise from the warming of the oceans and melting of glacial ice due to human-caused climate change, this flooding will not only become more frequent, but also more damaging and costly.
By 2050, sea level is projected to rise about a foot across the U.S., but that is forecast to be higher in the Tampa Bay area. A NOAA report released last year found that relative sea level rise from 2005 to 2060 is projected to be 27 inches in St Petersburg. Sea levels are rising twice as fast in the Gulf of Mexico than the average rate of the globe.
Over the course of a year from May 2023 to April 2024, NOAA predicts the U.S. will experience four to nine high tide flood days — about three times as many as typically occurred in 2000. The increase this year is due not only to sea level rise, but also El Niño, which is expected to cause stormier winter weather.
By 2050, the nation is expected to experience an average of 45 to 85 high tide flood days per year, depending on the region of the country.
Slowing climate change by reducing the burning of fossil fuels will help reduce the pace of sea level rise and allow more time for humanity to adapt, as well as curb the eventual peak in sea level.
But due to the excess heat already stored in the climate system from global warming, the ice will continue to melt. Thus several feet of sea level rise — at least — is already baked into the system into the next century, regardless of the measures we take.