Last week's weather pattern continued to hold a more summer-like regime across the Palmetto State. A strong surface and upper-level ridge held over the region; hot and humid conditions persisted, with no severe weather reported, through the seven-day period.
On Monday, September 10, light southeasterly flow kept a moist air mass positioned over the state, with a slight chance of diurnal showers and thunderstorms forming along weak surface boundaries and interaction with the sea-breeze. Tropical Storm Gordon formed off the southeast of Florida and moved northwestward toward the Gulf Coast. The storm posed no threat to South Carolina and any deep tropical moisture associated with the storm remained south of the state. High temperatures across the state on Monday and Tuesday were about 5 degrees above normal, with the National Weather Service (NWS) stations in Clemson, Greenville-Spartanburg Airport and Pickens observing high temperatures in the low to mid-90's.
The high pressure remained centered over the Mid-Atlantic during the mid-week. On Wednesday, September 5, the NWS station in Clarks Hill broke the record high minimum temperature value for the third consecutive day in a row. Many stations in the Midlands reported temperatures in the mid-to-upper 90's, with a few locations pushing close to 100 degrees. Even some of the cooler stations in the Upstate measured temperatures in the mid-to-upper 80's, such as the NWS station at Table Rock which reported a high temperature of 88 degrees. By Thursday, September 6, the upper-level ridge began to slightly weaken, but temperatures remained well above normal. The NWS station Batesburg reported a high temperature of 94 degrees, which tied the record maximum temperature set back in 1921. The continued period of below-normal rainfall in parts of the state led members of the United States Drought Monitor to expand the dry conditions (D0) to include much of the Pee Dee region and the introduce moderate drought conditions (D1) in Lancaster County, and parts of Chester, Chesterfield, Fairfield and Kershaw counties.
The CoCoRaHS Station at Charleston 2.9 NNE reported a 24-hour rainfall total of 4.50 inches on the morning of Friday, September 7, from an intense localized thunderstorm the previous day. According to the observer, the rain only lasted for 45 minutes, with the heaviest precipitation occurring during a 15-minute period. Friday evening marked the start of King Tides, associated with the perigean spring tide, when the new moon is closest to the earth, that lasted through the weekend. The Charleston Harbor tidal gauge observed an astronomical high tide value of 7.03 ft. mean lower low water (MLLW) around 7:00 p.m. Friday. Typically, shallow coastal flooding begins along the lower South Carolina coast when tide levels reach 7.0 MLLW in the harbor. Astronomical high tides values of 7.08 ft. MLLW and 7.54 ft. MLLW were reported on Saturday and Sunday, respectively. Many roads in downtown Charleston were covered due to the saltwater flooding, including the intersection of Highway 17 and Highway 61 near downtown.
Over the weekend, all eyes were focused on the Atlantic Ocean and Hurricane Florence, as forecasts had the storm potentially making landfall along the East Coast of the United States during the week of September 10.
(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 | 0.84 | 40.10 | 9.4 |
| Greer Airport | 0.11 | 36.83 | 3.2 |
| Charlotte, NC Airport | 0.71 | 32.48 | 2.9 |
| Columbia Metro Airport | 0.25 | 23.61 | -9.6 |
| Orangeburg Airport | 0.85 | 29.93 | -4.8 |
| Augusta, GA Airport | 0.18 | 31.39 | -0.5 |
| Florence Airport | 0.00 | 32.02 | 0.3 |
| North Myrtle Beach Airport | 0.12 | 38.43 | 0.8 |
| Charleston Air Force Base | 0.26 | 38.48 | 0.8 |
| Savannah, GA Airport | 1.28 | 27.77 | -8.2 |
| *Weekly precipitation totals ending midnight Sunday. |
4-inch depth soil temperature: Clinton: 78. Columbia: 81 degrees. Barnwell: 75 degrees. Mullins: 71 degrees.
Another week of sparse rainfall across the state during the week of September 3 – 9 led to a continued drop off in streamflow values in some of the area creeks and rivers; especially in the upper Pee Dee region. The Lynches River near Bishopville is reporting streamflow of 73.7 cubic feet per second (CFS), below the minimum flow of 95.6 CFS in 2009. Other rivers across the state, such as the Broad River near Carlisle, the Edisto River near Orangeburg and Givhans and the Little Pee Dee near Galivants are now reporting below normal streamflow values. Only portions of the Lowcountry and some isolated locations in the Piedmont and Upstate received any measurable rainfall. Most of the rainfall that fell during this week was less than 1.50 inches, with higher amounts in localized areas. Only a few rivers across the state, such as the Reedy River near Greenville and the Santee River near Pineville, reported much above normal streamflows going into the week of September 9.
Charleston Harbor (CHTS1): 86.4 degrees.
Capers Nearshore Buoy (Station 41029): 84.6 degrees.
Fripps Nearshore Buoy (Station 41033): 84.2 degrees.