Sunday Storm (17 Dec)

A few updates on the nor’easter blowing up the east coast as of 7am Sunday, it’s moving a bit more slowly than forecast, winds haven’t reached the Savannah area yet, but the rain is accumulating: over 2″ here at Daffin Park. The forecast is for conditions to deteriorate over the next few hours with the worst of it probably around noon, although winds will pick up this afternoon. Winds are not onshore yet; both Savannah International and Hunter Army Airfield are reporting around 10-12 mph, but at Grays Reef it’s is 35 gusting 45 mph. 

Rain should continue until noon, so we may pick up another couple of inches. Winds are also forecast to pick up this afternoon, so the latest says the high winds and heavy rain will be separated in time. This is because the highest winds are forecast to happen over coastal Georgia from the back side of the storm; for Charleston and points north, the two should be more in sync.

Still a chance for a strong thunderstorm in the next hour or two, although the risk for that (or an isolated tornado) seems a bit less than it looked yesterday. And of course once the winds start gusting there will be scattered power outages.

Another concern is coastal flooding: the forecast for Fort Pulaski at the 11am high tide is now 10. feet, but in looking at the gauge data I don’t think it will make it that high and around 9.5 is more likely. Just for the record if it does, here is what the official NWS guidance says for various stages …

At 10.0 ft MLLW, moderate coastal flooding occurs. Shipyard Rd will be impassable, isolating residents on Burnside Island. Water will start to encroach on HW-80 and as the tide gets closer to 10.5 ft MLLW, could begin to cover portions of the roadway. Flooding will expand on Tybee Island and Catalina Dr and Lewis Ave will be impassable. Flooding will also impact Wilmington Island, the Coffee Bluff community, Ossabaw Island, Sapelo Island, and portions of HW-17 south of Darien.

At 9.5 ft MLLW, minor coastal flooding occurs. Flooding will begin to impact Shipyard Road to Burnside Island. Parts of Ft Pulaski National Monument will begin to flood, including several trails. Flooding will also begin to impact Tybee Island including Catalina Dr and Lewis Ave. In Bryan County, water could breach docks near Ft McAllister and flooding will impact portions of Mill Hill Rd. In Liberty County, flooding impacts the Halfmoon Landing area and Cattle Hammock Rd near Bermuda Bluff subdivision.

By tonight this should have cleared out of Georgia and the South Carolina Lowcountry, perhaps some lingering wind gusts and showers north of Charleston. Further north, Hatteras will get a good storm, New England some wind and rain but as with us nothing likely to be terribly hazardous, just inconvenient.