An unsettled pattern set-up dominated the weather during the week, bringing a series of frontal systems into the region through the week.
A CoCoRaHS station in Salem reported a 24-hour total ending on the morning of Monday, February 18, of 1.25 inches as the cold front that moved into the state on Sunday, February 17, continued to push east throughout the Lowcountry. Despite the cool morning low temperatures in the lower 40's, temperatures across the state were able to rebound into the mid-to-upper 60's, between five and ten degrees above normal. The Charleston Harbor tidal gauge observed an astronomical high tide value of 7.35 ft. mean lower low water (MLLW) on Monday morning, which caused shallow coastal saltwater flooding in low-lying areas. Colder air moved into the region on Tuesday as a pronounced cold air damming pattern set up, as high pressure along the Eastern Seaboard built along the lee side of the Appalachians. The combination of cold air and increased moisture resulted in wintry precipitation across the mountains and foothills of the Upstate. Multiple reports of sleet were made throughout the morning in Chester, Greenville, Lancaster, Pickens and Spartanburg counties, with some light accumulation on grassy areas. At the coast, west-southwest flow prevailed, leading to another morning of high astronomical tides. Low-lying areas flooded again across the coastal areas, as the Charleston Harbor gauge recorded a maximum high tide level of 7.44 ft MLLW. High temperatures on Tuesday were ten to fifteen degrees cooler than Monday across the area. The National Weather Service (NWS) station located at the Florence Regional Airport recorded a high of 71 degrees on Monday, but only a high of 55 degrees on Tuesday.
The rainy pattern continued into the middle of the week for much of the Upstate as a series of low-pressure systems from the Gulf of Mexico travelled across the state. The 24-hour rainfall totals ending on Wednesday, February 20, reported from an inch and a half up to two inches in Abbeville, Anderson, Greenville and Oconee counties. The CoCoRaHS station near Due West measured 1.90 inches, while less than a tenth of an inch was observed in much of the Pee Dee and Lowcountry. Another morning of high astronomical tides occurred along the coast, as the Charleston Harbor tidal gauge recorded an 8.03 ft MLLW, and major flooding of the coastal area typically occurs when the gauge reaches 8.0 ft. Flooding due to saltwater occurred in low-lying roads and yards around Charleston, Edisto Beach, Folly Beach, the Isle of Palms and Kiawah Island, and their impacts were on par with the flooding that was experienced during the beginning of December 2018. High temperatures across much of the state struggled to get to the mid-40's, which was not much warmer than the morning temperatures which were in the upper-30's.
On Thursday, February 21, rainfall totals reported by CoCoRaHS stations in Oconee, Pickens and Spartanburg counties were over two inches, including a total of 2.46 inches reported by a CoCoRaHS observer near Chesnee. The continued period of below-normal rainfall in parts of the state led members of the U.S. Drought Monitor to add dry conditions (D0) in much of the Pee Dee region and included all of Georgetown and Charleston counties. Dry conditions were also introduced into coastal portions of Beaufort and Colleton counties. With the cold air damming still in place over the state, temperatures ranged from the low 60's in the Upstate to the low 80's near the coast. The NWS station located at the Charleston International Airport tied the record high temperature for the day of 82 degrees, set back in 1991 and the station in Beaufort also reached 82 degrees, breaking the previous record of 81 degrees from 1991.
The wet pattern would persist through Friday and into the weekend for much of the Upstate and portions of the Piedmont, as a backdoor cold front slipped across the state. On Friday morning, many of the CoCoRaHS stations in Greenville, Spartanburg and York counties reported between an inch and two inches of rain had fallen. Areas of the Midlands, Lowcountry and Pee Dee reported less than a quarter inch of rain. While low temperatures across the state were in the upper 40's to low 50's, the maximum temperature at the NWS stations at the Anderson, Greenwood and Rock Hill/York County airports only rose to 59 degrees, while the station at the Charleston International Airport hit 75 degrees. Light rain was once again in the forecast for Saturday, February 23. Under cloudy skies and the influence of the cold air damming pattern, the temperatures at many locations not along the coast remained in the mid 40's throughout the entire day. Sunday, February 24, started with clouds and drizzle across much of the state, and many stations reported either a trace or measurable stations for their eight or more days since February 14. By the mid-afternoon, a strong cold front moved through the region, bringing a drier air mass and ample sunshine across the state. Behind the front, gusty winds blew through the state. The NWS station at the Clemson/Oconee Airport reported a maximum wind gust of 44 mph, and a station on Sassafras Mountain recorded a maximum wind gust of 40 mph. Other stations across the Midlands measured wind gusts between 35 and 40 mph, as temperatures steadily dropped throughout the rest of the day.
(Note: The highest and lowest official temperatures and highest precipitation totals provided below are based on observations from the National Weather Service Cooperative Observer network and the National Weather Service's Forecast Offices.)| Weekly* | Since Jan 1 | Departure | |
|---|---|---|---|
| Anderson Airport | 3.17 | 9.93 | 2.8 |
| Greer Airport | 3.93 | 11.99 | 4.8 |
| Charlotte, NC Airport | 3.66 | 10.04 | 3.8 |
| Columbia Metro Airport | 0.39 | 3.86 | -2.8 |
| Orangeburg Airport | 0.11 | 4.26 | -2.7 |
| Augusta, GA Airport | 0.39 | 5.47 | -1.8 |
| Florence Airport | 0.41 | 4.16 | -1.6 |
| North Myrtle Beach Airport | 0.38 | 3.01 | -3.6 |
| Charleston Air Force Base | 0.41 | 2.35 | -3.9 |
| Savannah, GA Airport | 0.41 | 3.43 | -2.7 |
| *Weekly precipitation totals ending midnight Sunday. |
4-inch depth soil temperature: Clinton: 43 degrees. Columbia: 54 degrees. Barnwell: 49 degrees. Mullins: 43 degrees.
Rainfall totals across the Palmetto State for the previous seven days ranged from less than half an inch in portions of the Lowcountry to over eight inches in parts of the Upstate. Above normal streamflow values were reported for most of the rivers, creeks and streams in the northern portions of the state due to the heavy rainfall. Parts of the Broad, Congaree and Saluda rivers rose to minor and moderate flood stages. Greenville, Oconee, Pickens and Spartanburg counties' rainfall totals are between four and eight inches above normal since the beginning of the year. The Midlands and interior portions of the Lowcountry and Pee Dee regions of the state are reporting slightly below normal to near normal rainfall. Stream flow values are close to normal flows for this time of year but could trend up as last week's heavy rain moves through the river systems. Along the coast, the continued lack of rainfall in portions of Charleston, Georgetown and Horry counties is between four and six inches below normal since the beginning of the year.
Charleston Harbor (CHTS1): 58.6 degrees.
Capers Nearshore Buoy (Station 41029): 56.8 degrees.
Fripps Nearshore Buoy (Station 41033): Not Available.
