High pressure moved into the region on Monday, April 24, and provided sunshine, dry weather, and cooler-than-normal temperatures at the start of the week. Lows on Monday were in the upper 40s to mid-50s, while high temperatures were unseasonably cool, only reaching the upper 60s, Tuesday morning temperatures were the coldest during the period, dropping into the upper 30s in the Upstate, but were near 60 degrees at the coast. High temperatures were slightly warmer, ranging from the upper 60s to mid-70s. The high pressure shifted offshore late Tuesday, and moisture returned Wednesday morning, with an approaching cold front from the northwest and a stationary front offshore, increasing chances of showers and thunderstorms across the state. A few thunderstorms moved through the Midlands, and pea-sized hail was reported in Calhoun County. Under cloudy skies, high temperatures in some Upstate locations only reached the upper 50s, up to twenty degrees below average. In comparison, the National Weather Service (NWS) station at the Charleston International Airport reached 80 degrees.
The unsettled weather period continued Thursday and Friday as a low-pressure system formed along the northern Gulf coast, and the stationary front transitioned to a warm front. Widespread scattered showers increased in coverage and intensity as a warm front lifted northward over the state. Rain totals from Thursday night through Friday morning in the Upstate ranged from two to four inches, with isolated amounts over five inches. The rainfall caused the river heights of small creeks and streams in the impacted area to rise rapidly, and NWS Greer Office reported minor flooding on Huff Creek in Simpsonville.
Saturday started with clear skies, with a few high clouds, allowing temperatures to warm into the mid-80s across much of the state. As a cold front moved through Saturday evening, it produced another round of rain and thunderstorms. The late evening and early morning storms had strong winds, and some stations and offshore buoys reported wind gusts up to 45 mph. Storm spotters reported pea-sized hail in Sumter County. Behind the front, a cooler and drier air mass started to move into the region. Daytime temperatures were in the 70s but felt somewhat cooler due to the breezy conditions.
(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 | 3.08 | 21.33 | 5.5 |
| Greer Airport | 5.48 | 25.18 | 8.7 |
| Charlotte, NC Airport | 3.18 | 17.64 | 3.2 |
| Columbia Metro Airport | 2.18 | 19.15 | 5.9 |
| Orangeburg 2 (COOP) | 1.68 | 18.21 | 3.2 |
| Augusta, GA Airport | 2.79 | 22.60 | 8.1 |
| Florence Airport | 0.80 | 16.11 | 3.8 |
| North Myrtle Beach Airport | 1.74 | 11.94 | -0.6 | Charleston Air Force Base | 0.89 | 12.12 | -0.9 |
| Savannah, GA Airport | 1.68 | 13.49 | 0.5 |
| *Weekly precipitation totals ending midnight Sunday. M - denotes total with missing values. s - denotes total with suspect data. |
4-inch depth soil temperature: Clinton: 57 degrees. Columbia: 65 degrees. Barnwell: 61 degrees. Mullins: 64 degrees.
The unsettled pattern during the latter half of the period produced widespread rainfall across the state. Rainfall totals ranged from half an inch south and east of the Interstate 95 corridor, while the rest of the state recorded between one and two inches of rain. The storms that moved through the Upstate on Wednesday evening produced the heaviest rain, totals between four and six inches in portions of Cherokee, Greenville, and Spartanburg counties. The most recent United States Drought Monitor map showed abnormally dry (D0) conditions in parts of Berkeley, Charleston, Dorchester, Georgetown, and Williamsburg counties.
Due to the excessive rainfall in the headwaters of the Broad and Santee Rivers, the 14-day averages for most of the stream flow values in this watershed rose to much above normal values. River heights in areas impacted by the heavy rain rose into minor flood stages, with a few gauges approaching moderate flood stages before they started to fall at the beginning of the new work week. Elsewhere, most stream flow gauges remained at normal values, with most of the river gauge heights below the action stage; however, the river height gauge on the Santee River near Jamestown continued to rise as water moved through the watershed at the end of the period.
