With the potential landfall of Hurricane Florence somewhere on the Carolina coast later this week, this analysis could not have been better timed. Just as many of these events below are tied to hurricanes, Hurricane Florence could follow in their stead and dump large amounts of rain.
Below is a table of the 10 highest 24-hour rainfalls measured in South Carolina history (as of August 31, 2018) with date, nearest location, and precipitation.
Top 10 24-hour Rainfall Totals Measured in SC History (1849 – August 2018):
|1||09/16/1999||Myrtle Beach, SC||14.80″|
|2||09/16/1999||Brookgreen Gardens, SC||14.71″|
|4||10/04/2015||Mount Pleasant, SC*||13.17″*|
|5||08/27/1995||West Pelzer, SC||12.81|
|8||09/15/1999||North Myrtle Beach (Airport), SC||12.04″|
For * and **, see Data quality notes for this article below.
- Many of these events are either directly or indirectly tied to tropical weather, so I’m going to start out by linking these events:
- #1, #2, and #8 – Hurricane Floyd
- #3 and #6 – 1916 South Carolina Hurricane – made landfall north of Charleston, SC, in Bulls Bay.
- #4, #7, and #9 – not a hurricane itself, but an extratropical storm tapped into Hurricane Joaquin to feed it moisture. Many names have been given to this one, including “The Great Flood of 2015.”
- #5 – Tropical Storm Jerry
- #10 – Hurricane Matthew
- Hurricane Floyd’s rain totals are quite impressive in South Carolina. The fact that 3 of the top 10 are on this list (including the top 2) is made all the more impressive as the system did not make landfall in the state. In the direction the hurricane is moving, the right side of it often has the heaviest winds and rains. This portion of the hurricane would have been in North Carolina at landfall, showing the power of Floyd to still set all-time precipitation records.
- Further reading – Good article from the Raleigh Weather Field Office (WFO) of the National Weather Service (NWS).
- Hurricane Floyd’s rain totals were magnified in the Pee Dee and Grand Strand of SC by the heavy rains that fell in North Carolina (als0 record-setting). Many rivers, including the Waccamaw, the Lumbee, and the Pee Dee flow from sources North of the border. This caused already swollen SC rivers to flood at epic levels.
- Since every one of these records is linked directly or indirectly to hurricanes/tropical storms, the geographical distribution makes sense as 9 of the 10 records are below the fall line, staying closer to the coast.
- It is strange that Hurricane Hugo did not make this list considering the amount of destruction it caused this state. Without digging deeply, I’m guessing that Hugo was moving faster than any of the storms on this list. A slow, weak storm like Tropical Storm Jerry can dump more rain than a fast, powerful Hugo.
- Other than Floyd, further reading for each of the storms listed:
- 1916 South Carolina Hurricane – article in the Sumter Item, which published an article and images from the South Carolina Historical Society.
- The Great Flood of 2015:
- A good overview article from Wikipedia.
- A narrative in PDF format from SCDNR about the storm and the resulting flooding – (SCDNR Link | Alternative PalmettoPonderings Link)
- Not often I would recommend content from weather.com; however, this article has a lot of good visuals and also images of the storm’s effects.
- Interactive experience through SCDNR and ArcGIS.
- Spring 2016 newsletter of Carolina CoCoRaHs in PDF format, covering the flood and the importance of volunteer data contribution. Good map data. (Alternative PalmettoPonderings Link)
- Hurricane Matthew:
- Good total rainfall map from the Greenville, SC WFO of the NWS.
- Great writeup from the Wilmington, NC WFO of the NWS. This WFO covers the Pee Dee and Grand Strand of SC.
- PalmettoPondering’s compilation of Tweets on Hurricane Matthew
- Tropical Storm Jerry:
- Good overview of storm from Storm Prediction Center.
All-Time South Carolina Weather Series:
- Top 10 Hottest Temperatures in South Carolina History
- Top 10 Coldest Temperatures in South Carolina History
- Top 10 Highest Daily Rainfalls in South Carolina History (this article)
Data quality notes for this article:
- 1) An entry was deleted for Rock Hill, SC (GHCN ID: USC00317363) on 08/29/1940 for 13.13″ due to the fact that there was no other station supporting it spatially or on the same order of magnitude. The next closest rainfall observed on the same day was for 3-4″ of rain. The SC State Climate Office also disregards this in their listing of York County’s precipitation record. However, the NCDC did not flag for a quality error.
- 2) An entry was deleted for Reevesville, SC (GHCN ID: US1SCDC0018) on 10/08/2016 for 12.90″ due to rejection by the SC State Climate Office for Dorchester County’s participation record. I believe that it doesn’t have great spatial support due to the fact that the station is in the upper part of the Dorchester County and none of the other top 10 entries from the date are from Dorchester. Again, the NCDC did not flag for a quality error.
- * – #4 is not recognized by the State Climate Office for Charleston County’s precipitation record. However, I think that the entry is spatially supported on that date and the number is within reason.
- ** – #7 is not recognized by the State Climate Office for Richland County’s precipitation record. Again, I think that the entry is spatially supported on that date and the number is within reason.
About this data:
As a part of a series exploring South Carolina weather, I have compiled a complete database of quality-controlled data from the National Climatic Data Center (NCDC), a part of the National Oceangraphic and Atmospheric Administration (NOAA). This data uses observations from all kinds of sources that are quality-checked by the NCDC to ensure that these are precise measurements. In case you are interested, and I have cited below, the subset used is the Global Historical Climatology Network – Daily, containing summary of the day measurements from all kinds of sources.
Menne, M.J., I. Durre, B. Korzeniewski, S. McNeal, K. Thomas, X. Yin, S. Anthony, R. Ray, R.S. Vose, B.E.Gleason, and T.G. Houston, 2012: Global Historical Climatology Network – Daily (GHCN-Daily), Version 3.24. NOAA National Climatic Data Center. http://doi.org/10.7289/V5D21VHZ 2018-09-03.