On Monday, September 30, the remnants of Helene, along with an upper level over the Ohio Valley, shifted east toward the Mid-Atlantic, and with the southerly flow, a few showers developed during the afternoon and evening over portions of the northern Midlands and Pee Dee. Rainfall totals were minimal, with a CoCoRaHS observer near Fort Mill reporting a 24-hour total of 0.85 inches by Tuesday morning. Both features eventually moved off the coast on Tuesday as a weak cold front approached the area. Temperatures remained slightly above average, with highs in the low to mid-80s. Low-level northerly flow developed on Wednesday, and the weak, dry cold front moved through the region.
A dry surface high pressure built in the north of the region on Thursday, October 3, leading to quiet weather inland and slightly above-normal temperatures through the weekend. Morning temperatures over the weekend started in the 60s and, under sunny skies, climbed into the mid- to upper 80s. However, due to gusty northeast winds and long-period swells, there was a moderate risk of rip currents along the entire coast on Thursday and Friday. These conditions also prompted small craft advisories for the coastal waters through the weekend.
The tidal levels at the Charleston Harbor gauge ranged between 7.04 and 7.13 feet MLLW Thursday through Saturday evening, causing shallow saltwater flooding in low-lying coastal areas.
(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 | 0.00 | 46.09 | 10.2 |
| Greer Airport | 0.00 | 47.26 | 8.8 |
| Charlotte, NC Airport | 0.01 | 45.55 | 11.3 |
| Columbia Metro Airport | 0.00 | 45.72 | 9.3 |
| Orangeburg 2 (COOP) | 0.00 | 41.03 | 0.00 |
| Augusta, GA Airport | 0.00 | 39.38 | 3.8 |
| Florence Airport | 0.00 | 43.46 | 6.8 |
| North Myrtle Beach Airport | 0.00 | 43.78 | 4.9 | Charleston Air Force Base | 0.03 | 47.86 | 4.6 |
| Savannah, GA Airport | 0.01 | 49.27 | 9.5 |
| *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: 76 degrees. Barnwell: 71 degrees. Mullins: 68 degrees.
Conditions were dry in Helen's wake, with most of the state recording less than a tenth of an inch of rain and many places reporting no rain during the period. Scattered showers on Monday produced a few rainfall totals near a quarter of an inch, and locations in the northern Midlands, especially Lancaster and York counties, measured between half an inch and an inch of rain ending on Wednesday morning. The remainder of the period was dry across the state. Due to the rainfall from Helene during the previous period, all drought and abnormally dry conditions were removed from the U.S. Drought Monitor map released on Thursday, October 3.
Even though the period was dry, the 14-day average streamflow values at most of the gauges across the state’s watersheds report values much above average. River heights in the Broad, Santee, and Pee Dee river basins were still in moderate and minor flood stage as the rainfall from Helene continued to make its way out of North Carolina and through the state. The Santee River at Jamestown crested in a major flood stage at 23.94 ft on October 5, and the Savannah River at both Burton's Ferry and near Cylo was in minor flood stage and still rising at the end of the period.
