The two main weather stories during the period were the Arctic air over the region and the winter storm that produced snow over the state.
On Monday, January 20, maximum and minimum temperatures were between fifteen to twenty degrees below normal due to a deep trough and surface high pressure that aided in pushing Arctic air into the central and eastern United States. Morning temperatures dropped into the teens in the Upstate to the lower 30s at the coast, while high temperatures struggled to reach the 40s. Temperatures remained cold on Tuesday, up to thirty degrees below normal, and high temperatures did not get out of the 30s. The National Weather Service station at the Charleston International Airport recorded a high of 38 degrees. With cold, Arctic air entrenched across the region, a low-pressure system that moved along the Gulf Coast brought wintry precipitation across the state during the late afternoon and evening hours. The precipitation started as snow across the Midlands and freezing rain in the Lowcountry before changing to snow. By Wednesday morning, most of the Lowcountry had received between two and four inches of snow and sleet, while portions of the Pee Dee recorded up to five inches of snow, with isolated amounts of six inches.
Behind the storm system, skies cleared, and dry weather returned to the area, although the below-normal temperatures continued through the weekend. With ample sunshine, snow that melted on Wednesday afternoon froze overnight as low temperatures dropped into the teens and low 20s across the state, causing black ice, which led to hazardous driving conditions on Thursday morning. The freezing temperatures continued through the early afternoon but warmed enough to help continue melting away lingering snow. Despite a warming trend that lasted through the remainder of the period, temperatures were below normal, with highs reaching the mid-40s by Friday and the mid-50s by Sunday.
(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 | 0.02 | 1.23 | -2.2 |
| Greer Airport | 0.01 | 1.25 | -2.3 |
| Charlotte, NC Airport | 0.02 | 0.95 | -2.0 |
| Columbia Metro Airport | 0.07 | 1.20 | -1.8 |
| Orangeburg 2 (COOP) | 0.20 | 2.12 | -1.2 |
| Augusta, GA Airport | 0.17 | 2.83 | -0.4 |
| Florence Airport | 0.03 | 1.29 | -1.3 |
| North Myrtle Beach Airport | 0.23 | 1.11 | -0.9 | Charleston Air Force Base | 1.15 | 1.95 | -0.9 |
| Savannah, GA Airport | 0.71 | 1.21 | -1.5 |
| *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: 45 degrees. Barnwell: 37 degrees. Mullins: 42 degrees.
The only precipitation to fall during the period occurred with the storm system that moved through the region on Tuesday and Wednesday. Snowfall totals ranged from 6.0 inches in portions of the Pee Dee, including Georgetown and Horry counties, to trace amounts in the Upstate. The precipitation began as rain and freezing rain in the Lowcountry, with ice accumulation totals of up to 0.25 inches in isolated locations of Beaufort County, before it transitioned to snow late Tuesday night and early Wednesday morning. Over the seven days, liquid precipitation totals were highest in the Coastal Plain, with amounts up to an inch and a half, and isolated higher amounts.
The U.S. Drought Monitor map released on Thursday, January 23, showed some deteriorating conditions in the Pee Dee, and a moderate drought (D1) designation was expanded from the Pee Dee into portions of the northern Midlands, to include parts of Chester, Kershaw, Lancaster, Lee, and York counties. Elsewhere, drought conditions remained the same across the state. Any changes in the USDM drought designations from rainfall during the latter half of the period will be reflected in the map released on Thursday, January 30, because it fell after Tuesday morning's data cutoff.
Due to the continued lack of beneficial rain in portions of the state, many of the 14-day average streamflow values from gauges in the Upstate dropped to below-normal levels, with some gauges on small tributaries reporting values much below normal. Values within the Pee Dee basin remained below normal, with the gauge on the Waccamaw River near Longs and the Little Pee Dee River at Galivants Ferry reporting below-normal values. Most gauges in the ACE, Lower Santee, and Lower Savannah river basins continued to report values within the normal ranges. The river height levels along the river and the tidal gauges remained below the flood stage during the period.
