WEEKLY SOUTH CAROLINA WEATHER 2020
September 21 - September 27, 2020
WEATHER SUMMARY:
The continued King Tide event marked the start of the period. The high astronomical tides caused sunny day saltwater flooding in Charleston and other locations along the coast. The tidal gauge at the Charleston Harbor reported values of 8.03 feet mean lower low water (MLLW) on Monday evening, September 21. The crests on Tuesday and Wednesday were slightly lower, with the event ending on Wednesday evening.
Canadian surface high pressure dominated the weather pattern through midweek, with dry conditions and many locations around the state reporting daytime temperatures below normal. On Monday, the National Weather Service (NWS) station in Spartanburg recorded a new low maximum temperature of 70 degrees, breaking the previous record of 73 degrees in 1991. Not to be outdone, the NWS station at Caesar’s Head broke the prior record of 60 degrees in 1982 with a reported low maximum on Tuesday, the 22nd, of 57 degrees. The high pressure moved offshore on Wednesday; however, it still provided the region with dry weather and seasonable temperatures.
The remnants of Tropical Storm Beta passed over the area Thursday night through Saturday morning. The main threats from Beta were damaging winds, isolated tornadoes, and heavy rain. On Friday, September 25, a waterspout moved onshore at North Myrtle Beach and moved parallel to the beach and dunes, causing damage to umbrellas, chairs, and storage bins before it disappeared. The official NWS storm survey estimated the maximum winds at 75 mph and rated the tornado as an EF0. Heavy rains to the south and east of the Interstate 20 corridor caused flooding in some areas, including downtown Summerville and in popular areas around the Charleston Market. Temperatures warmed into the lower 80s, though locations in the Piedmont and Upstate struggled to reach 70 for a high temperature.
By Saturday, the low-pressure system moved offshore, isolated rainfall lingered behind with cloudy skies settling into the region. Some early morning foggy conditions occurred over the weekend in the Midlands with visibility reported less than two miles at the NWS stations at the Columbia Metropolitan Airport, Florence Regional Airport, Greenwood County Airport, Orangeburg Municipal Airport, and the York County Rock Hill Airport. In areas where the stratus layer burned off, mainly along the coast, daytime temperatures rose into the mid-80s, while the rest of the state only reached the low to mid-70s.
(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.)
The highest temperature reported was 90 degrees on September 26 at the NWS station located in Barnwell.
The lowest temperature reported was 36 degrees at the NWS station located near Jocassee in Oconee County on September 23.
The maximum 24-hour precipitation reported was 3.00 inches at the NWS station in Summerville in Dorchester County, ending on the morning of September 26.
The CoCoRaHS station Darlington 0.3 ENE (SC-DR-33) reported a 24-hour precipitation total of 4.93 inches, ending on the morning of September 26.
The state average precipitation for the seven-day period was 0.8 inches.
PRECIPITATION:
| | Weekly* | Since Jan 1 | Departure |
| Anderson Airport | 0.74 | 50.19 | 17.2 |
| Greer Airport | 1.34 | 58.92 | 23.3 |
| Charlotte, NC Airport | 1.46 | 42.30 | 10.8 |
| Columbia Metro Airport | 0.45 | 48.00 | 12.9 |
| Orangeburg Airport | Trace | 35.16 | -1.5 |
| Augusta, GA Airport | 0.19 | 49.84 | 16.1 |
| Florence Airport | 2.05 | 52.17 | 18.4 |
| North Myrtle Beach Airport | 0.57 | 43.39 | 2.3 |
| Charleston Air Force Base | 0.60 | 45.38 | 4.2 |
| Savannah, GA Airport | 0.75 | 43.34 | 4.8 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
SOIL TEMPERATURES:
4-inch depth soil temperature: Clinton: 70 degrees. Columbia: 73 degrees. Barnwell: 68 degrees. Mullins: 64 degrees.
PRECIPITATION AND RIVER STAGES:
The main precipitation event during the period occurred with the passage of the remnant low associated with Tropical Storm Beta toward the end of the workweek. Limited rainfall fell during the start of the period, while rainfall from Thursday to Saturday was widespread. Most of the state reported at least half of an inch of rainfall. Radar estimates show that portions of northern Florence County received up to seven inches of rainfall, and CoCoRaHS observers in the area measured between two and six inches of rain. However, some locations in the Central Savannah River Area and Lowcountry measured less than a quarter of an inch. Most of the year-to-date rainfall totals across the state continued to be above-normal through the middle of September, with the recent rains bringing totals in areas that were drier closer to normal.
With the additional rainfall from the remnants of Tropical Storm Beta occurring on the heels of Hurricane Sally, most of the USGS streamflow data across the state rose for the second week in a row. Most of the gauges recorded much above-normal conditions to high conditions. Many of the river levels south of the Fall Line reached minor to moderate flood stage and continued to rise through the period steadily. As the water pushed through the basins, gauges in the Lowcountry started to increase slightly. Both streamflow values and river stage heights will continue to be elevated as the rainfall moves through the river basins.
WATER TEMPERATURES:
Charleston Harbor (CHTS1): 76.1 degrees.
Capers Nearshore Buoy (Station 41029): 75.9 degrees.
Fripps Nearshore Buoy (Station 41033): 77.0 degrees.
