The period started with temperatures up to fifteen degrees above normal. Low temperatures on Monday, November 4, were in the upper 50s to low 60s and daytime high temperatures were in the mid- to upper 70s. On Tuesday, some locations had morning lows in the upper 60s, over twenty degrees above normal. Fog formed across portions of the Midlands and Pee Dee regions, reducing visibility to less than a mile. On Tuesday afternoon, high pressure extended into the area from the northeast, and due to the onshore flow, there were some scattered showers over the state.
Heavy rain started across portions of Orangeburg, Aiken, Lexington, Calhoun, Bamberg, Dorchester, and Colleton counties on the afternoon of Wednesday, November 6, due to interactions between a stalled front across the Southeast U.S. and deep tropical moisture from the Caribbean and tropical Atlantic. This led to training cells along a line from Barnwell County through lower Richland/western Sumter counties. By Thursday morning, radar estimates showed over a foot of rain across portions of Orangeburg County, an uncommon event, especially for November, which is typically one of the drier months. The excessive rainfall caused multiple road closures, breaching dams, and water rescues in the impacted areas. More information on rainfall totals and river impacts can be found in the section below.
Temperatures continued to be mild despite cloudy conditions on Thursday, with some locations reporting highs in the upper 70s to low 80s. Patchy early morning fog dropped visibilities to under a quarter of a mile across the Coastal Plain on Friday morning. The well-above-normal temperatures continued Friday, and the National Weather Service (NWS) station at the Charleston International Airport reported a high temperature of 85 degrees, tying the daily record set back in 1986. A cold front approached the region late Friday and moved through on Saturday. High pressure built in behind the front on Saturday, and the cooler and drier conditions led to temperatures being closer to normal. An upper-level disturbance produced another round of shower activity on Sunday afternoon and evening, with up to an inch of rain falling in areas impacted by the heavy rain earlier in the period.
(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 | 0.47 | 46.60 | 7.2 |
| Greer Airport | 1.06 | 48.70 | 6.3 |
| Charlotte, NC Airport | 0.73 | 46.47 | 8.7 |
| Columbia Metro Airport | 2.63 | 48.5 | 8.7 |
| Orangeburg 2 (COOP) | 9.03 | 50.06 | 5.4 |
| Augusta, GA Airport | 5.52 | 44.90 | 6.5 |
| Florence Airport | 0.65 | 44.12 | 4.1 |
| North Myrtle Beach Airport | 0.11 | 43.99 | 0.8 | Charleston Air Force Base | 1.83 | 49.69 | 2.3 |
| Savannah, GA Airport | 4.96 | 54.28 | 11.0 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. s - denotes total with suspect data. |
4-inch depth soil temperature: Clinton: Not Available. Columbia: 69 degrees. Barnwell: 65 degrees. Mullins: 68 degrees.
Areas south of Interstate 20 and west of Interstate 26 received more than three inches of rain in the middle of the week due to a stalled frontal boundary across the region. A CoCoRaHS station near North in Orangeburg County reported 12.45 inches by Thursday morning, with most of that falling overnight. Additional CoCoRaHS observers in Aiken, Allendale, Bamberg, Calhoun, and Lexington counties reported between five and ten inches of rain. Outside of the area impacted by the event Wednesday night into Thursday morning, the rest of the state recorded less than half an inch of rain, with some locations in the Pee Dee and Upstate reporting less than a tenth of an inch of rain.
The U.S. Drought Monitor map released on Thursday, November 7, reflected the continued drier-than-normal with abnormally dry (D0) conditions expanding across the entire state, with only a small area of Lancaster and York counties near the Charlotte area showing no drought classification. The moderate drought (D1) area in the Coastal Plain expanded into parts of the interior Lowcountry and was introduced in Georgetown, Horry, and Marion counties. Any changes in the USDM drought designations from rainfall during the later half of the period will be reflected in the map released on Thursday, November 14, because it fell after Tuesday morning's data cutoff.
Rainfall from the heavy rain event during the middle of the week caused the 14-day average streamflow values at most of the gauges across the ACE Basin and Lower Savannah River watershed to report values much above average, including a few gauges, like the Salkehatchie River near Miley, that had been experiencing low flows due to the persistent dry conditions. In response to the locally observed heavy rain, river height gauges rapidly rose into the moderate and major flood stage. The North Fork of the Edisto River at Orangeburg reported a preliminary crest of 15.34 feet, higher than the record crest of 15.30 feet set in February 1925. The South Fork Edisto River near Bamberg crested at 15.30 ft, surpassing the previous record of 13.71 feet set in May 1998. By the end of the period, river heights in the headwaters had dropped though gauges in the lower portions of the watersheds were still rising or starting to crest.
