The news about high tide flooding isn’t good, and if the scientists with the National Oceanic and Atmospheric Administration are accurate, it’s only going to get worse.
Nicole LeBeuf, acting director of the NOAA National Ocean Service, said work in Norfolk, Va., brought home those realities.
“Some of my key takeaway lessons were, 1. coastal flooding is a very complex issue, 2. addressing it will require resources, expertise and efforts by many partners, and 3. we cannot wait to act,” LeBeuf said. “This issue only gets more urgent and more complex with each passing day. Ultimately, I came away with a greater understanding of what coastal communities are facing, and how NOAA can assist and inform local sea-level rise efforts now and going forward.”
NOAA runs a national water level observation network with 210 real-time sensors that collect data through the coastal states and Great Lakes, with data collected every six minutes. Some of the stations involved have data records more than a century old.
“Because we have these long, continuous high-quality data records, we’re also able to track and provide information on things like sea-level rise and high tide flooding, and how these things can vary from location to location, and change over time,” said Greg Dusek, chief scientist with NOAA’s Center for Operational Oceanographic Products and Services. “This network is what really enables us to provide the State of High Tide Flooding and Outlook report that we’re talking about today.”
The report looks at the number of days of high tide flooding across the country for 2018, with estimates for 2019. And it bears mentioning these are meteorological years — May 2019-April 2019 and May 2019-April 2020. The report also takes a look at estimates out to 2030 and 2050.
“In 2018, the national median high tide flood frequency hit five days, and tied the all-time record set in 2015,” said William Sweet, oceanographer with NOAA CO-OPS. “Relative sea levels — again, the U.S. median — were over 31 centimeters, or about 1 foot, higher than they were in 1920. This is the second-highest level in about the last 100 years.
“Twelve individual locations, out of those 98 that we’re tracking, broke or tied their individual high tide flood records. The National Weather Service’s forecast offices also issued record numbers of coastal flood advisories to the public, so this really is a weather-meet-climate story.”
For the Georgia bight, the decadal trends indicate annual high tide flooding not only increasing but accelerating.
According to the report, “Bounded by a range of (relative sea level) rise under a lower and continued-high emission rate, today’s national (high tide flood) frequency of five days … is likely to increase to about 7–15 days by 2030 and 25–75 days by 2050 (HTF range: low emission-high emission values), with much higher rates in many locations.”
Fernandina Beach’s gauge notched its record nine days of high tide flooding in 2015, while Fort Pulaski set its 16-day mark in 2016. For 2030, Fernandina is estimated to have 9-15 high tide flooding days, and 25-70 by 2050. Fort Pulaski is to fare worse, with 15-25 flooding days by 2030 and 40-95 days by 2050.
The report is on The News website along with this story, but a storymap based on the report can be found at tidesandcurrents.noaa.gov/HighTideFlooding_AnnualOutlook.html.