After multiple weeks of severe weather, a tranquil weather pattern and seasonable temperatures were the stories for much of the period.
Stations across the state reported gusty winds, up to 25 mph, and low humidity continued from Sunday into Monday, May 11, increasing the fire weather for the start of the workweek. Another front continued to move offshore, providing another surge of cold and dry air into the region. Morning and daytime temperatures were ten degrees below normal, with low temperatures in the 40s and highs reaching the low to mid-70s. The dry and cool weather continued into Tuesday, causing morning lows to be near twenty degrees below normal. The National Weather Service (NWS) station at the Anderson FAA Airport recorded a minimum temperature of 40 degrees, breaking the previous record of 42 degrees set back in 1960. The NWS stations at the Greenville-Spartanburg International Airport and Columbia Metropolitan Airport tied their record lows for the day with 38 degrees and 40 degrees, respectively. The maximum temperature of 72 degrees at the NWS station at Beaufort MCAS, broke the previous record low maximum temperature of 73 degrees set back in 1989.
Throughout the remainder of the week, the drier weather continued, and temperatures started to moderate to near normal for mid-May. High temperatures warmed into the low to mid-80s on Wednesday, Thursday, and Friday afternoon, reaching the low 90s in some locations by the weekend.
On Thursday, the National Hurricane Center began watching a system over the Bahamas for potential development. But late on Saturday, May 16, data from the Hurricane Hunter reconnaissance mission into the system east of Florida showed the depression had strengthened into the first tropical storm of the 2020 hurricane season and was designated as TS Arthur. A tropical storm watch was issued for portions of the North Carolina coast. The storm was forecasted to remain well offshore but would cause rip currents and significant waves along the coast and provide moisture into the region over the weekend.
(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 | Trace | 28.54 | 11.6 |
| Greer Airport | Trace | 32.32 | 14.6 |
| Charlotte, NC Airport | 0.02 | 21.80 | 6.4 |
| Columbia Metro Airport | 0.00 | 18.50 | 3.4 |
| Orangeburg Airport | 0.00 | 15.45 | -0.4 |
| Augusta, GA Airport | 0.01 | 22.61 | 6.5 |
| Florence Airport | 0.01 | 17.47 | 3.8 |
| North Myrtle Beach Airport | 0.01 | 17.28 | 1.6 |
| Charleston Air Force Base | 0.00 | 18.47 | 3.7 |
| Savannah, GA Airport | 0.00 | 20.76 | 6.1 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
4-inch depth soil temperature: Clinton: 72 degrees. Columbia: 73 degrees. Barnwell: 67 degrees. Mullins: 67 degrees.
Minimal rainfall was measured during the period, with the highest seven-day total of 0.08 inches reported by a CoCoRaHS observer in Lancaster County. Many NWS stations reported a trace or a tenth of an inch of rainfall. With the lack of rainfall, soils began to dry out in portions of the state. In the Lowcountry, impacts from the continued dry conditions were noted due to the lack of rain since the beginning of the month.
The USGS streamflow data across the state showed most of the gauges reported conditions are near-normal to slightly above average at 14- and 28-days, though a few streamflow values have fallen below 25 percent.
