On Monday, May 20, high pressure was centered over the Southeast, with cool, dry air across the region. Morning temperatures were in the mid-50s in the Upstate to the lower 60s at the coast, and daytime temperatures were in the upper 70s to low 80s. The high pressure dominated the weather pattern, providing dry and fair conditions through mid-week. Temperatures started a warming trend on Tuesday, with afternoon temperatures five to ten degrees above average throughout the remainder of the period, with highs in the upper 80s to mid-90s by Thursday afternoon.
The Charleston Harbor Tidal Gauge recorded a high astronomical tide of 7.19 feet MLLW on Monday, which caused shallow flooding in low-lying coastal areas. The tides were also slightly elevated on Tuesday and Wednesday evenings.
The calm weather conditions gave way as the high pressure moved off the coast, and a weak upper-level disturbance passed near the area, producing isolated showers in the Upstate on Thursday. An approaching cold front triggered more widespread showers and thunderstorms on Friday, with some storms reaching severe limits. Wind damage, mainly in the form of downed trees, was reported in Jasper, Beaufort, Greenville, Orangeburg, McCormick, Colleton, Aiken, Richland, Fairfield, Union, Florence, Sumter, Berkeley, Anderson, and Pickens counties. Some severe storms produced hail, including golf ball-sized hail reported in Greenville and Spartanburg counties. The unsettled weather continued over the weekend, with highs climbing into the mid-90s temperatures and heat indices reaching the upper 90s in portions of the Midlands and Coastal Plain.
(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 | 0.12 | 24.62 | 5.7 |
| Greer Airport | 1.08 | 27.10 | 7.3 |
| Charlotte, NC Airport | 0.54 | 22.33 | 5.2 |
| Columbia Metro Airport | 0.02 | 20.34 | 4.3 |
| Orangeburg 2 (COOP) | 0.00 | 15.10 | -3.1 |
| Augusta, GA Airport | 0.28 | 15.19 | -1.7 |
| Florence Airport | 0.36 | 16.90 | 1.6 |
| North Myrtle Beach Airport | 1.17 | 15.26 | 0.3 | Charleston Air Force Base | 0.24 | 18.95 | 3.5 |
| Savannah, GA Airport | 0.82 | 19.52 | 3.6 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. s - denotes total with suspect data. |
4-inch depth soil temperature: Clinton: 75 degrees. Columbia: 77 degrees. Barnwell: 73 degrees. Mullins: 65 degrees.
The first part of the period was dry; however, unsettled weather started on Thursday and lingered through the holiday weekend. Much of the state received less than a quarter of an inch of rain, and the areas that received more rainfall ranged from half an inch to over two inches. Multiple CoCoRaHS observers in Richland County reported over two inches of rain from storms on Friday, while other observers in isolated parts of the Lowcountry and Pee Dee received over an inch.
The 14-day average streamflow values across the state reported typical values, though some gauges in the Midlands and Pee Dee regions recorded flows much above normal. Despite the increased flows, river height gauges across the state remained below the action stage, and gauges within the Coastal Plain fell from the minor flood stage due to the relatively dry week. Tidal gauges reached the action stage along the coast at the beginning of the period, with only a few reports of minor shallow tidal flooding.
