Warm and breezy conditions were observed ahead of a cold front, which moved through the region late on Monday, December 4. Some high clouds in the morning gave way to clearing skies as drier air filtered into the area. Maximum and minimum temperatures were about ten degrees above normal, with morning lows in the mid- to upper 40s and daytime highs in the upper 60s to low 70s. High pressure settled into the Southeast by Tuesday afternoon. Temperatures were cooler than Monday and closer to normal for the beginning of December. Overnight lows were in the mid- to upper 30s, and highs were in the low to mid-60s.
Another cold front moved through late Wednesday, and breezy northwest winds ushered in a cooler air mass. Overnight temperatures dropped below freezing across much of the state due to clear skies and calm winds, setting up favorable radiational cooling conditions. The National Weather Service (NWS) stations at the Florence Regional Airport and the Greenville-Spartanburg International Airport recorded a low of 26 degrees on Thursday morning. Despite the clear and sunny skies, maximum temperatures were in the mid- to upper 50s.
The high pressure that settled into the Deep South in the middle of the week shifted off the coast and provided southerly winds on Friday, allowing for a gradual warming trend that lasted through the rest of the period. Low temperatures on Friday morning rebounded from the mid-20s to the upper 60s by late afternoon. A wedge of cold air kept temperatures in the 50s in the Upstate. In comparison, high temperatures on Saturday reached the upper 70s across the Midlands and Pee Dee regions ahead of an approaching cold front responsible for producing multiple long-track tornadoes in portions of Kentucky and Tennessee. Widespread showers with embedded thunderstorms were observed throughout most of Sunday as the cold front pushed through the region. Some storms produced wind gusts up to 50 mph across portions of the Midlands, Pee Dee, and Lowcountry, and a few offshore and coastal locations measured gusts up to 55 mph. Temperatures quickly dropped behind the front as cooler and drier air moved back into the area.
(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 | 1.34 | 43.82 | 0.5 |
| Greer Airport | 1.49 | 48.88 | 2.4 |
| Charlotte, NC Airport | 2.15 | 42.21 | 1.1 |
| Columbia Metro Airport | 0.90 | 51.78 | 9.2 |
| Orangeburg 2 (COOP) | 0.50 | 54.87 | 7.9 |
| Augusta, GA Airport | 1.07 | 59.37 | 18.1 |
| Florence Airport | 0.40 | 43.32 | 0.5 |
| North Myrtle Beach Airport | 0.85 | 39.44 | -6.9 | Charleston Air Force Base | 0.07 | 47.83 | -2.3 |
| Savannah, GA Airport | 0.30 | 37.72 | -8.2 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. s - denotes total with suspect data. |
4-inch depth soil temperature: Clinton: 54 degrees. Columbia: 60 degrees. Barnwell: 55 degrees. Mullins: 65 degrees.
Conditions were mainly dry through the work week, with a cold front providing rain across the state on Saturday and Sunday. The highest rainfall totals were in the mountains, where totals up to four inches were recorded at stations in the higher elevations. Over two to three inches of rain were reported in Chester, Fairfield, and York counties. Locations in the Lowcountry and Pee Dee recorded totals up to half an inch. The rainfall came after the December 7 release of the US Drought Monitor (USDM) map, which continued to reflect the extreme (D3) drought conditions across parts of the Upstate and the severe (D2) and moderate drought (D1) conditions in portions of the Midlands and Pee Dee regions.
Dry conditions during the previous period and most of this period led to a deterioration of streamflow values across much of the state. The 14-day average streamflow values in portions of the Broad, Catawba, Pee Dee, Lynches, and Saluda river basins dropped much below normal, with less than a dozen stations reporting normal flows. While the river height gauges across the state reported levels below flood stage, tidal gauges reached the action stage (below flood stage) on Sunday due to astronomically high tides.
