The last King Tide cycle for 2020 lasted through midweek, and the tidal gauge in the Charleston Harbor reached 7.66 ft MLLW on Monday morning and 8.02 ft on Wednesday morning. There were multiple reports of saltwater flooding in downtown Charleston and low-lying areas along the entire coast. On Monday, December 14, a strong cold front moved through the region during the morning, and showers ended across the state by midday. Behind the front, breezy conditions, with wind gusts up to 40 mph, caused Lake Wind Advisories to be issued by the National Weather Service (NWS). Temperatures were above normal, with minimums in the low 40s and daytime highs in the upper 60s. However, cooler air pushed into the state overnight, and under cloudy skies, daytime temperatures struggled to reach the 50s.
By Wednesday, a low-pressure system formed off the coast of Florida and strengthened as it passed offshore. With a wedge of high-pressure north of the area, it funneled unseasonably cool temperatures into the state. High temperatures were close to twenty degrees below normal. The NWS station at the Charleston International Airport reported a low of 43 degrees and only a high of 46 degrees. There was widespread rain across much of the area and reports of freezing rain early morning in portions of the Upstate. Up to half an inch of freezing rain accumulated on tree branches near Caesars Head and Tuxedo in Greenville County. Cloudy and cold conditions lingered on Thursday before high pressure built in from the Plains.
The cool, dry weather dominated the weather on Friday and through the weekend, with high temperatures in the upper 40s, moderating to the mid-50s by Saturday. A low pressure developed in the Southeast and lifted through the region on Sunday, bringing moisture back into the region. Light rain fell across much of the state on Sunday morning under mid-level clouds, keeping high temperatures in the upper 40s and low 50s.
(Note: The highest and lowest official temperatures and highest precipitation totals provided below are based on observations from the National Weather Service (NWS) Cooperative Observer network and the National Weather Service's Forecast Offices.)| Weekly* | Since Jan 1 | Departure | |
|---|---|---|---|
| Anderson Airport | 0.85 | 59.41 | 16.6 |
| Greer Airport | 1.49 | 72.83 | 27.0 |
| Charlotte, NC Airport | 1.59 | 58.02 | 17.5 |
| Columbia Metro Airport | 1.03 | 54.55 | 11.1 |
| Orangeburg Airport | 0.63 | 42.91 | -2.8 |
| Augusta, GA Airport | 0.80 | 54.35 | 12.0 |
| Florence Airport | 1.03 | 60.77 | 19.0 |
| North Myrtle Beach Airport | 0.90 | 53.54 | 2.6 |
| Charleston Air Force Base | 0.71 | 52.89 | 3.0 |
| Savannah, GA Airport | 1.09 | 49.79 | 2.9 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
4-inch depth soil temperature: Clinton: 47 degrees. Columbia: 54 degrees. Barnwell: 47 degrees. Mullins: 43 degrees.
During the period, widespread totals of at least half an inch of rain fell across the Palmetto State. Some portions of the northern Midlands measured closer to two inches. Because of the additional rain, streamflow gauges across the state remained at values that were near or slightly above normal. Even with the rain, though the streamflow values were high, the river heights in the upper portions of these basins remained below flood stage. Despite some of the recent rains, parts of the Lowcountry, especially around the Lower Savannah, are still abnormally dry. The year-to-date rainfall totals across the state are near normal, though portions of the Pee Dee and Upstate are reporting more than fifteen inches above normal. Some locations in these regions could report one of their wettest years on record.
