Coastal storm to bring tidal flooding, rain for Wednesday

/ December 15, 2020 at 9:21 PM

This evening, a coastal low is beginning to develop off the Georgia coast. This low will move northward tonight into tomorrow, eventually turning into quite the nor’easter for New England. Locally, expect periods of showers to continue tonight into Wednesday as the low lifts northward and a cold front approaches from the west. Temperatures will remain chilly, only topping out in the low 50s in the afternoon. The front will clear the area during the evening, giving way to drier air for Thursday.

Moderate coastal flooding expected with the 9:05am high tide

As the low develops offshore, onshore winds on top of lingering astronomical king tides will cause water levels to reach well into moderate coastal flooding territory (between 7.5′ and 7.99′ MLLW). This may force the closure of several roads in downtown Charleston, particularly on the west side of the peninsula, and also around the City Market and on Lockwood Drive by the Charleston City Marina.

NWS noted in this evening’s forecast discussion that there is a possiblity for tides to make a run at major coastal flood status (8’+ MLLW) with the development of the low offshore. We’ll want to watch this closely as more road closures would undoubtedly result from tides exceeding 8′. If we do see another major coastal flood event, that would be seven for the year, breaking the record of 6 set in 2015 and recently tied in 2020. If major coastal flooding appears likely, the National Weather Service will hoist a Coastal Flood Warning, a step above a Coastal Flood Advisory.

Regardless of whether we reach 8′ or not tomorrow morning, expect disruptions during the morning commute due to closed roads if peninsular Charleston is on your route. One good thing: Any rain that will be in the area should remain light, and not make the situation worse.

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