The week started with a cold front moving through the area on Monday, December 30. The boundary provided some scattered showers during the morning, and the National Weather Service (NWS) station in McClellanville reported 0.95 inches from the early morning rainfall. As the front moved offshore, clearing skies and drier conditions moved into the region. Morning low temperatures were in the upper 40s to mid-50s; which was up to 30 degrees warmer than normal and higher than the normal maximum temperatures for the time of year. Daytime highs reached the upper 60s to lower 70s along the coast, including 73 degrees recorded at the NWS station at the Charleston International Airport. On the last day of 2019, conditions were breezy, cooler, and dry. Low temperatures rose from the upper 30s to low 40s into the upper 50s and low 60s. Wind gusts across the state ranged from 25 mph to 30 mph.
Over the next couple of weeks, the State Climate Office will finalize and post a 2019 Year-in-Review report.
The continued cool and dry conditions ushered in the start of 2020 on Wednesday. Minimum temperatures dropped into the mid and upper 30s, with the NWS stations in Spartanburg and Walhalla reporting lows of 27 degrees. Under clear skies, temperatures rebounded into the upper 50s and low 60s. Another low-pressure developed along the Gulf Coast and pushed a warm front into the area by Thursday. The frontal system began to move through the area Thursday evening, and bringing rain that lingered across the region through early Saturday morning. With the warm front positioned north of the state, temperatures climbed into the mid-70s, nearly 25 degrees above normal in the Midlands. The NWS station at the Florence Regional Airport set a new daily maximum temperature record of 76 degrees, and the station in Batesburg tied the record of 75 degrees set back in 1910. While the rainfall on Friday was mainly a result of showers, there were a few stronger embedded storms as the front moved across the state. Wind gusts from some of the stronger thunderstorms downed trees in parts of the Midlands, and storm spotters reported trees blocking roads near Jackson in Aiken County.
By Saturday, January 4, the remaining isolated rain showers moved out of the region, and conditions began to dry out behind the front. Rainfall totals over the event ranged from less than 0.25 inches at the coast to over three inches in the Upstate. Strong winds, up to 50 mph, behind the front prompted Lake Wind Advisories across portions of the state. These non-thunderstorm winds downed trees in Anderson County near Williamston and a WeatherFlow station near Fort Sumter reported a maximum 49-mph wind gust. The windy conditions continued into the evening hours but had eased by Sunday morning, as dry conditions with near-normal temperatures prevailed for the remainder of 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 | 2.22 | 2.16 | 1.4 |
| Greer Airport | 2.47 | 2.47 | 1.9 |
| Charlotte, NC Airport | 1.19 | 1.19 | 0.6 |
| Columbia Metro Airport | 1.75 | 1.70 | 1.2 |
| Orangeburg Airport | 1.10 | 0.81 | 0.2 |
| Augusta, GA Airport | 1.66 | 1.38 | 0.8 |
| Florence Airport | 1.67 | 0.90 | 0.4 |
| North Myrtle Beach Airport | 0.32 | 0.20 | -0.4 |
| Charleston Air Force Base | 0.14 | 0.09 | -0.5 |
| Savannah, GA Airport | 0.48 | 0.27 | -0.3 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. |
4-inch depth soil temperature: Clinton: 48 degrees. Columbia: 54 degrees. Barnwell: 48 degrees. Mullins: 47 degrees.
The rainfall over the past few weeks caused the 2019 annual rainfall totals to rebound to near normal across much of the state. However, areas in the mountainous Upstate are higher. Some of the rainfall totals in the Upstate were over 75 inches, including locations near Keowee Key, Sunset and Table Rock, while some stations, such as the Anderson Airport, recorded less than 40 inches for the year. Many stations reported rainfall totals between 43 and 55 inches, but there were still locations in the Lowcountry and Midlands that had below normal values.
| 2019 Totals | Departure | |
|---|---|---|
| Anderson Airport | 39.36 | -4.9 |
| Greer Airport | 51.09 | 4.9 |
| Charlotte, NC Airport | 54.03 | 12.4 |
| Columbia Metro Airport | 42.26 | -2.3 |
| Orangeburg Airport | 31.15 | -15.6 |
| Augusta, GA Airport | 50.87 | 7.3 |
| Florence Airport | 45.37 | 2.5 |
| North Myrtle Beach Airport | 55.99 | 4.0 |
| Charleston Air Force Base | 49.45 | -1.6 |
| Savannah, GA Airport | 51.36 | 3.4 |
Most of the rainfall during the period was the result of a low-pressure system that pushed through the region on Thursday and Friday. To start 2020, most of the National Weather Service stations and CoCoRaHS observers across the state reported at least half an inch of rain over the seven days. However, portions of the Upstate recorded between two and three inches of rain, and streamflow values in the areas impacted by the heaviest rains remained above normal for another week.
