Last year, Hampton Roads experienced a record-breaking number of days with flooding from high tides – among the most on the East Coast, according to the National Oceanic and Atmospheric Administration.
The agency projects slightly fewer tidal flooding days for the region this year, in line with national trends. But a strong hurricane season could increase flooding regardless, scientists said.
NOAA released the data Tuesday with its annual high tide flooding outlook, which it has produced every year since 2015. The report covers the period between May and the following April.
The agency’s definition of high tide flooding is when tides reach between 1 to 2 feet above the daily average high tide, and cover typically dry coastal land. It can happen without storms, but can also make flooding more severe during periods of heavy rain and wind.
Hampton Roads is all too familiar with the issue, known as nuisance or sunny day flooding. NOAA oceanographer Karen Kavanaugh even cited Norfolk residents as an example during a call with reporters Tuesday.
“They're facing traffic delays dropping their kids off to school or getting to work, because there's water that's flooding the streets, and not necessarily because of a storm,” Kavanaugh said.
“These impacts accelerate and accumulate over time and become more and more damaging. But even in the short term, it's something that people need to be aware of and mitigate.”
Tidal flooding is increasing nationwide alongside sea level rise fueled by climate change.
Low-lying Hampton Roads is particularly susceptible, in part due to a high rate of sinking land.
The Mid-Atlantic has seen a more than 200% increase in high tide flood days since 2000, NOAA says.
But last year’s surge was largely driven by the El Niño weather pattern, which increases flooding along the Atlantic coast through changes in winds and storm activity.
Other places along the coast also tied or broke their cities’ records last year, including New York City, Baltimore and Atlantic City in New Jersey.
Norfolk’s previous record of high tide flooding days was 15. Last year, the city hit 23 – about 10 more than NOAA had projected. This year, officials predict that’ll go down to between 11 and 15.
Along the Eastern Shore, the agency says to expect up to 17 days of high tide flooding.
NOAA last year rolled out a more detailed tool to predict flooding for any given day of the year specifically tied to high tides. The digital calendar is updated monthly and available online.
