An intense low-pressure system north of the area provided breezy and cool conditions that started off the period on Monday, November 30. The National Weather Service (NWS) station located at the Charleston International Airport recorded wind gusts up to 50 mph as the associated cold front pushed through the state. Daytime highs were reached in the morning hours and then steadily fell throughout the day as high pressure started to build into the region.
On Tuesday, December 1, the start of meteorological winter, the main story was the bitterly cold high temperatures, with many locations reporting temperatures up to twenty degrees below normal. Many places struggled to get out of the 40s for daytime highs, including typically warmer areas along the coast such as Beaufort, Charleston, and Myrtle Beach. The NWS station at Long Creek in Oconee County reported a high of 37 degrees, which broke the previous low maximum record of 38 degrees set back in 1967. Under clear skies, the overnight temperatures plummeted into the low to mid-20s, and hard freezes were reported in the Upstate and Midlands by Wednesday morning.
The mostly calm weather remained throughout the period as the high pressure continued in control of the pattern. With sunny skies, temperatures rose from the 20s into the mid and upper 50s. While overnight temperatures were still cool, temperatures continued to warm, and some stations reached the 60s on Thursday. A low-pressure system moved into the region on Friday afternoon, and moisture flowed into the area ahead of the cold front. Most of the rain fell during the late evening, with the heaviest rainfall totals falling in portions of the Midlands and Upstate. A few CoCoRaHS observers in Aiken, Richland, and Saluda counties measured over an inch of rain. As the front moved through the area, some locations in the Midlands reported wind gusts up to 40 mph, including a USGS station at Lake Murray.
Lingering showers on Saturday morning gave way to breezy conditions by the afternoon. Temperatures fell over the weekend as cooler and drier air re-entered the region once again behind the cold front. The drier airmass remained across the area through the beginning of the new work week.
(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 | 1.94 | 58.54 | 17.6 |
| Greer Airport | 2.09 | 71.33 | 27.4 |
| Charlotte, NC Airport | 1.29 | 56.43 | 17.4 |
| Columbia Metro Airport | 0.88 | 53.21 | 11.2 |
| Orangeburg Airport | 0.35 | 42.17 | -2.0 |
| Augusta, GA Airport | 0.43 | 53.30 | 12.5 |
| Florence Airport | 0.30 | 59.51 | 19.1 |
| North Myrtle Beach Airport | 0.44 | 52.58 | 3.3 |
| Charleston Air Force Base | 0.21 | 52.08 | 3.6 |
| Savannah, GA Airport | 0.33 | 48.70 | 3.2 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
4-inch depth soil temperature: Clinton: 46 degrees. Columbia: 56 degrees. Barnwell: 48 degrees. Mullins: 40 degrees.
The rain fell in a similar pattern for a second week in a row, with the highest rainfall totals reported in the Upstate, with some locations reporting seven-day totals up to three inches. The strong cold front that pushed through the region Sunday night into Monday morning provided most of the rainfall during the period. Much of the state measured rainfall totals between half an inch up to two inches. However, some locations east of the Interstate 95 corridor reported less than a third of an inch of rainfall. The year-to-date rainfall totals across the state continue to be above-normal, mainly due to the wet start to 2020. Despite the recent rainfall, portions of the Lowcountry are still experiencing abnormally dry conditions, especially in areas near the Lower Savannah.
With much of the heavy rains during the period falling over the Upstate, streamflow gauges in the Upper Broad and Yadkin-Pee Dee river basins continued to measure values well above normal. Even though the streamflow values were high, the river heights in the upper portions of these basins remained below flood stage. Rain elsewhere across the state helped keep streamflow values near normal, and river height gauges at the end of the basins showed some levels at minor flood state but were slowly dropping.
