The work week started with a cold front continuing to push slowly across the state. A lingering boundary along the coast produced heavy rain for portions of Beaufort, Charleston and Jasper counties. The CoCoRaHS stations in the area measured two to three inches of rain during the overnight hours, and ahead of the front, temperatures on Monday, December 3, continued to be above normal for this time of year. A daily high minimum temperature record of 61 degrees at the National Weather Service (NWS) Cooperative Weather station in Lake City broke the previous record of 58 degrees set back in 1941. High temperatures across the state ranged from the mid-60's in the Upstate to the mid-70's near the coast. The high temperature of 67 degrees at the NWS station at the Greenville-Spartanburg Airport and the 71-degree maximum temperature at the Myrtle Beach Grand Strand Airport were both 10 degrees above normal. Once the front pushed through the state, a cold and dry high pressure centered over Oklahoma built into the region on Tuesday, December 4, and remained in control of the weather pattern through Thursday. Maximum temperatures across the state on Tuesday were considerably colder behind the front, with the highest temperature reported for the day of only 63 degrees at the NWS station at the Charleston International Airport.
Despite the sunshine on Wednesday, breezy northwest winds helped keep temperatures below normal as high temperatures at many locations across the state struggled to get into the mid-50's. The NWS station at the Greenwood County Airport recorded a high of 47 degrees, and the McClellanville station reported a maximum temperature of 54 degrees. The tranquil weather continued into Thursday, with the surface high pressure settling across the Southeast, ahead of a storm system that brought significant rains to portions of California, and would eventually impact the Palmetto State over the weekend. With clear skies, radiational cooling overnight allowed for temperatures to drop into the teens in the South Carolina mountains to around freezing at the coast. The NWS station in Anderson County had a low temperature of 23 degrees, and the station at the Wateree Dam in Kershaw County recorded a low of 25 degrees, new daily record lows at both locations. For the third day in a row, only trace amounts of precipitation were reported by both CoCoRaHS and NWS Weather observers. However, given the rain totals over the previous seven-day period, the Thursday, December 6 release of the U.S. Drought Monitor showed a decrease in the area of drought conditions in the Lowcountry. A one-category improvement was made across the region, with the complete removal of moderate drought (D1) conditions, and a 10% reduction in the area of dry conditions (D0); with only Hampton and Jasper counties still reporting some lingering drought conditions.
On, Friday, December 7, a weak frontal boundary, with limited moisture, moved quickly across the state and a high-pressure ridge behind the front extended from the Midwest into the mid-Atlantic region. The ridge provided a cold northerly flow, which helped develop a wedge/cold air damming event over the Carolinas. As the low-pressure system moved east across the Gulf of Mexico, the amount of moisture increased, bringing cloud cover and light rain into the state late Friday evening. The winter storm dominated the weather over the weekend and caused impacts from the Upstate to the coast. The event started as a cold rain across most of the state on the morning of Saturday, December 8, before the precipitation transitioned to snow and a wintry mix in the Upstate. Snowfall in the Upstate ranged from 2 to 12 inches, with a report of 11.9 inches in Inman in northern Spartanburg County. CoCoRaHS observers in Lyman, Slater-Marietta and Taylors measured between three and four inches of snow. The total storm snowfall of 4.3 inches at the NWS Greenville-Spartanburg Office in Greer makes it the second snowiest December on record since 1962. The warm air aloft cut into the snow accumulations but caused areas of sleet and freezing rain in portions of the Piedmont and Midlands. Sleet was reported in Union, Laurens, Pickens and Spartanburg counties, while up to a quarter of an inch of freezing rain was measured in York and Lancaster counties.
Heavy rains associated with the storm system soaked portions of the Midlands and Pee Dee regions during the weekend. The NWS station in McCormick reported a two-day total of 2.51 inches of rainfall. CoCoRaHS stations in Dillon, Florence, Sumter, Lexington, Richland and Horry counties reported over two inches of rainfall While temperatures were below normal for this time of year, the surface temperatures were too warm to support any significant wintry precipitation, though a few areas did see a brief change over to sleet, especially in Newberry County.
Along the coast the morning of Sunday, December 9, a wind advisory was issued with sustained winds up to 35 mph, wind gusts up to 45 mph. Stations offshore, such as the Capers Nearshore, Editso and Folly Buoys, measured wind gusts as high as 45 mph, while many stations directly along the coast, including Sullivans Island and the Folly Beach Pier, recorded wind gusts up to 40 mph. The Charleston Harbor tidal gauge reported a morning high tide of 8.05 ft. mean lower low water (MLLW); major flooding of the coastal area typically occurs when the gauge reaches 8.0 ft. Flooding due to saltwater occurred in low-lying roads and yards around Charleston, Edisto Beach, Folly Beach, the Isle of Palms and Kiawah Island. Further up the coast, areas around Pawley's Island in Georgetown County also experienced saltwater flooding because of the strong onshore winds combined with high tides. Strong wind gusts were also measured in other areas of the state, including the stations at the Anderson Airport (39 mph), Greenville-Spartanburg Airport (37 mph), Columbia Metropolitan Airport (34 mph) and Aiken County Airport (33 mph). The temperature gradient at the coast was impressive when the noon temperature in Summerville was 43 degrees, and it was 61 degrees in Mount Pleasant; a 12-degree difference across roughly 25 miles.
As the storm pulled off to the northeast at the end of the weekend, light rainfall and some wintry precipitation continued to fall over portions of the state.
(Note: The highest and lowest official temperatures and highest precipitation totals provided below are based on observations from the National Weather Service Cooperative Observer network and the National Weather Service's Forecast Offices.)| Weekly* | Since Jan 1 | Departure | |
|---|---|---|---|
| Anderson Airport | 2.99 | 57.48 | 16.1 |
| Greer Airport | 2.82 | 61.35 | 17.0 |
| Charlotte, NC Airport | 1.82 | 54.73 | 15.4 |
| Columbia Metro Airport | 2.24 | 45.61 | 3.3 |
| Orangeburg Airport | 1.27 | 42.21 | -2.3 |
| Augusta, GA Airport | 1.49 | 51.27 | 10.2 |
| Florence Airport | 2.07 | 54.17 | 13.5 |
| North Myrtle Beach Airport | 1.90 | 63.84 | 14.2 |
| Charleston Air Force Base | 1.68 | 51.99 | 3.3 |
| Savannah, GA Airport | 1.28 | 39.64 | -6.2 |
| *Weekly precipitation totals ending midnight Sunday. |
4-inch depth soil temperature: Clinton: 40 degrees. Columbia: 50 degrees. Barnwell: 44 degrees. Mullins: 38 degrees.
Rainfall totals over the past seven days were normal to below normal across the state, with portions of the Upstate receiving up to four inches of rain, and several inches of snow. The Central Savannah River Area (CSRA) and the Lowcountry received between half an inch to an inch and a half of rain and continued to be one of the drier parts of the state, with the annual rainfall total in this area measuring close to ten inches below normal. The amount of moderate rainfall over the weekend caused some flooding issues, especially in portions of the Lowcountry, as the rainfall trained over the area. The rainfall caused minor flooding in the lower portions of the Pee Dee watershed, with some moderate flooding along the Lumber River in NC. Most of the rivers across the state were running near full bank, and some minor flooding was still possible along with some rivers systems, including the Savannah, Congaree, and Santee. Rivers, creeks, and streams across most of the Palmetto State continued to report streamflow values that were much above normal for this time of year.
Charleston Harbor (CHTS1): 54.5 degrees.
Capers Nearshore Buoy (Station 41029): 56.1 degrees.
Fripps Nearshore Buoy (Station 41033): 56.3 degrees.
