With heavy snowfall having lashed the Upstate and much of North Carolina and Virginia, rain from the same system gave way to significant flooding that inundated roadways and low lying areas in parts of downtown Charleston on Sunday.
The Upstate region remained under a winter storm warning that will remain in effect until noon Monday, according to the National Weather Service. While areas east of the Upstate were spared from measurable snow accumulation, storm conditions yielded strong, wet winds and, at times, heavy rainfall locally. Heavy winds also produced gusts upwards of 35 mph in parts of the Charleston area.
Even with the arrival of the stormy weather, less than expected rainfall during Sunday morning's above-average high tide kept flood levels below officials' projections.
Charleston County was under a coastal flood warning Sunday morning that lasted through noon. The morning high tide around 9:30 a.m. initially coincided with a spattering of rain downtown, though all eyes were on heavier rainfall and winds descended upon the area in the early afternoon as the quick-moving system continued east.
While the latter bout of heavier rainfall Sunday afternoon did not significantly exacerbate already-existing flood conditions in low lying areas, it did, however, slow down the rate at which the tide levels dropped, said Emily McGraw, a meteorologist with the National Weather Service in Charleston. Although the tides were slow to come down, she added, the levels had already peaked and were falling by the time the heavy rainfall crept in around noon.
Levels at Charleston Harbor on Sunday peaked at 8.05 feet shortly before 10 a.m. and measured around 3.82 feet by 2 p.m., she said. The Charleston Harbor reaches flood stage at 7 feet.
"The (bulk of) the rain happened after (high tide), so that's what helped keep it down," said Rebecca Davidson, also a meteorologist with the NWS in Charleston.
Looking ahead to Monday, there is a chance of showers beginning in the early morning hours, though likely not enough to give way to flooding, McGraw added.
As the rain intensified Sunday afternoon, officials utilized temporary pumps in affected areas to help relieve flooded roads. Take the intersection of Gadsden and Bennett streets, for instance. A pump situated at the location helped to make the area, that would've otherwise been submerged, passable for pedestrians and motorists.
Flooding closed several downtown streets for much of Sunday, though most roads were reopened by late afternoon.
Just two weeks ago, much of downtown Charleston was deluged with flood waters that left vehicles stranded and overwhelmed roadways as unusually high tide levels persisted for three consecutive days, Nov. 23-25. The flooding at the time was especially peculiar as it extended inland as far as Hanahan and the Francis Marion National Forest.
Charleston recorded its sixth-highest tide on record, cresting at 8.76 feet, Nov. 24, which surpasses levels observed during the 1,000-year flood in October 2015.