High tide flood days will increase, says NOAA

NOAA projects the two National Water Level Observation Network stations on the Northern Neck―Lewisetta in Northumberland County and Windmill Point in Lancaster County―will experience more high tide flood days by 2050. (source: The State of High Tide Flooding and 2022 Outlook) Lewisetta is projected to experience 95-140 in 2050, up from 10 in 2021 and a predicted 9-14 this year. NOAA predicts 90-135 at Windmill Point in 2050, a dramatic jump from 11 in 2021 and a predicted 6-12 this year.

But high tide flooding is not restricted to these two sites. As the map below illustrates, virtually all coastal areas on the Northern Neck will experience greater high tide flooding. Red represents minor flooding events, according to NOAA, “which typically presents a low threat of property damage and no direct threat to life.” Yellow, on the other hand, represents major flooding events, events “which typically presents a significant threat to life and property.”

What is high tide flooding? According to NOAA,

High-tide flooding occurs in low-lying coastal areas during extreme high tides (also known as perigean or king tides). These tides occur a few times per year when the sun, moon, and earth align. By definition, a coastal storm is not necessary for high-tide flooding to occur. However, even relatively weak onshore winds can increase the level of flooding. (source: Understanding Stormwater Inundation)