National Overview - May 2016
Recurrent Coastal Flooding

« National Overview - May 2016

Recurrent Coastal Flooding

This month's State of the Climate report has, as a supplement, an annual update of the state of recurrent coastal tidal flooding, sometimes called "nuisance flooding" or "clear-sky flooding". Nuisance flooding occurs when a water level measured at a NOAA water level gauge exceeds the local elevation threshold for minor impacts established locally by the local Weather Forecast Office of the National Weather Service. While nuisance flooding is rarely life-threatening, it can be costly for building owners and infrastructure in general. Recurrent flooding can exacerbate these impacts.

The analysis brings forward several important points:

  1. On average for the nation, nuisance tidal flooding during 2015 generally exceeded historical averages. In many locations, the 2015 increase even exceeded the increasing rate suggested by trends in recent decades.
  2. On average for the nation, nuisance tidal flooding increased by more than 50% in 2015, compared to 2014.
  3. Several locations along the Atlantic Coast, Florida Peninsula and Gulf Coast experienced a record number of nuisance tidal flooding events during 2015.
  4. Much of the 2015 spike in events is related – directly or indirectly – to the presence of a strong El Niño during the year.
  5. For 2016, nuisance tidal flooding is projected to generally return to values suggested by long-term trends, which are increasing for the vast majority of locations.
  6. There are regional and seasonal exceptions or variations to the general national-scale trends and projections mentioned above.

The complete report can be found here.

Citing the complete report:

Sweet, William V. and John J. Marra, 2016: "2015 State of U.S. Nuisance Tidal Flooding." Supplement to State of the Climate: National Overview for May 2016, published online June 2016, retrieved on [date] from