The main story for the period would be the continued summertime precipitation pattern with diurnal convective thunderstorms and high temperatures in the mid-to-upper 90s, with heat index values climbing into the 100s through the first part of the week.
High pressure dominated the weather on Monday, July 20, with temperatures across much of the state five to ten degrees above normal, and reports of the mid-90s in the Upstate. The National Weather Service (NWS) station in downtown Greenville reported a high of 97 degrees. Heat advisories were issued for locations in the Upstate and Lowcountry with heat index values between 105 and 110 degrees on Monday and Tuesday. Late afternoon and early evening thunderstorms occurred that were spotty in coverage. There was no widespread severe weather, but individual storms produced heavy rain, hail, and strong winds. Some storms on Monday caused minor tree damage in Union County. On Tuesday, there were scattered reports of minor wind damage from pulse thunderstorms in Anderson, Greenville, Oconee, Spartanburg, and York counties.
By midweek, a weak low-pressure trough shifted toward the Mid-Atlantic, causing the upper high-pressure to move its position, allowing moisture to return across the area through the weekend. On Thursday, July 23, the National Hurricane Center was monitoring a low-pressure system in the Gulf that would become Hurricane Hannah and make landfall along the Texas Coast over the weekend. Tropical Storm Gonzalo continued to move westward in the southern Atlantic, with no threat to SC.
Temperatures returned to near normal values heading into the weekend. Some severe thunderstorms in the Midlands, mainly in Richland County, caused strong winds and pea- to nickel-sized hail. The nearly stationary storms produced heavy rain that caused flash flooding near Dentsville and Elgin. Over the weekend, atmospheric conditions were primed for waterspouts to form along the coast. Local news media outlets and observers reported several funnel clouds and waterspouts near Forest Beach, Folly Beach, and Isle of Palms. The highest rainfall totals over the weekend were in the Midlands and Pee Dee, with many areas across the state missing out on beneficial rainfall.
(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 | 0.17 | 40.94 | 15.8 |
| Greer Airport | 2.44 | 49.09 | 21.9 |
| Charlotte, NC Airport | 2.67 | 33.99 | 10.3 |
| Columbia Metro Airport | 2.48 | 36.06 | 10.4 |
| Orangeburg Airport | 0.54 | 26.26 | -1.0 |
| Augusta, GA Airport | 0.54 | 37.85 | 12.0 |
| Florence Airport | 1.55 | 39.73 | 15.4 |
| North Myrtle Beach Airport | 0.95 | 29.55 | 2.5 |
| Charleston Air Force Base | 0.42 | 29.56 | 2.1 |
| Savannah, GA Airport | 2.01 | 31.48 | 4.7 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
4-inch depth soil temperature: Clinton: 85 degrees. Columbia: 82 degrees. Barnwell: 76 degrees. Mullins: 74 degrees.
During the period, showers and thunderstorms were isolated across most of the state, and areas that received measurable rainfall were under slow-moving thunderstorms. Parts of the northern Pee Dee recorded over three inches, with one CoCoRaHS observer in Hartsville (Darlington County) reporting 6.02 inches from one storm. Hit or miss pockets of two plus inches dot the state, mainly from afternoon convective and sea breeze storms. Since the beginning of April, rainfall totals are near to above normal values across much of the state. However, the recent heat and lack of precipitation led to deteriorating conditions in portions of the Lower Savannah River Basin, Lowcountry, and Upstate. The lack of rainfall in these areas has led to reports of decreasing surface water supplies and drying topsoil in fields.
The USGS streamflow data across the state show most of the gauges are reporting normal to above-normal values at 14- and 28-days. Streamflows in the regions that did not receive any rainfall during the period have dropped off.
