High tides alone could cause flooding in Norfolk for up to 19 days this year, according to the National Oceanic and Atmospheric Administration.
That’s more than anywhere else on the East Coast and would be the area’s worst year of high tide flooding on record.
Within a few decades, Norfolk could see high tide flooding for about a third of the year.
The predictions are part of NOAA’s national high tide outlook released Tuesday, which covers the time period from this May through next April.
The outlook focuses on the type of disruptive tidal flooding Hampton Roads residents know well, also called nuisance flooding – the kind that can swamp intersections and close schools even on a sunny day.
NOAA defines high tide flooding as when tides reach between 1 to 2 feet above the daily average high tide and cover typically dry coastal land.
Low-lying Hampton Roads has long been susceptible to tidal flooding. But a combination of rising global sea levels and sinking land has increased that vulnerability.
“It no longer takes severe weather to cause disruptive flooding along the coast,” said Nicole LeBoeuf, assistant administrator for the National Ocean Service. “Clearly, high tide flooding is not just a regional but a national issue and is expected to accelerate well into the future.”
The agency’s data is based on a network of 98 tide gauges across the U.S., including Sewells Point along Naval Station Norfolk, as well as Kiptopeke State Park in Cape Charles.
For the latter, NOAA predicts between nine and 13 days of high tide flooding over the next year.
NOAA predicted 10 to 15 days of high tide flooding in Norfolk last year, which turned out to be accurate: the agency recorded 12. The area’s record is 15.
One factor driving the predictions this year is the presence of El Niño, a natural climate pattern that pushes warm water east.
Communities in the Mid-Atlantic and Gulf regions of the U.S. are expected to experience the most high tide flooding this year because El Niño conditions will compound the effects of sea level rise, LeBoeuf said.
The Mid-Atlantic has seen a 300% increase in flood days in the past two decades, NOAA says.
Officials say September and October will likely see the most high tide flooding in the region, tied to astronomical “king tides” that happen when the earth, sun, and moon are nearly in alignment.
In addition to its annual outlook, NOAA is now rolling out a more detailed tool to predict tidal flooding for any given day of the year.
You can look on a digital calendar, updated monthly, to see which days have the highest likelihood for flooding from high tides.
LeBoeuf said NOAA’s goal is always to prepare, not scare, people.
It’s up to local officials and communities to decide for themselves how to grapple with the new reality, she said.
“High tide flooding on an annual and now monthly basis is something that we can predict in these locations. And so we really just encourage you to … work it into your short term and long term plans if you're going to be around the coast for any period of time.”
