Winter Weather Awareness Week: What causes winter coastal flooding?
Stick around for day five of Winter Weather Awareness Week as News 12's Hope Osemwenkhae breaks down the services and alerts provided by the National Weather Service.
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Coastal flooding is common during the winter season. Sometimes flooding can be caused by nearby coastal storms, a full moon or just persistent onshore winds. Coastal floods can last for hours or even days, even on sunny and quiet days.
Coastal storms could also be called nor’easters, which is a low pressure system offshore along the east coast bringing a persistent gusty northeasterly wind. It can produce heavy rainfall, damaging winds and storm surge, or higher than normal astronomical tides. Strong northeast winds along the east coast can cause higher than normal astronomical tides, called storm surge. When storm surge coincides with higher astronomical tides and a full moon, the chance of coastal flooding is higher.
Onshore winds, tides, geography and topography are the main factors of what causes coastal flooding in a specific location. Persistent onshore winds can also cause large waves, which could lead to beach erosion and sand displacement. If weather conditions stay the same over several high tide cycles, tidal flooding becomes a bigger concern, especially with any slow-moving storms and a strong high-pressure system to the north, which can enhance these impacts.
The highest astronomical tides, called Perigean Spring tides, occur when there is a new or full moon coincident with it being at its closest elliptical orbit to the Earth (Perigee). The quiet weather flooding can be exacerbated by a persistent offshore low-pressure system sending waves and piling water along the coast.
With warmer winters becoming our new normal, heavy rain combined with snowmelt can also enhance the flood threat during the winter season. When coastal flooding occurs, remember to move your car to higher ground and never drive across flooded roadways.
Stick around for day five of Winter Weather Awareness Week as News 12's Hope Osemwenkhae breaks down the services and alerts provided by the National Weather Service.
