And, like a broken record, people are asking repeatedly, "When was the last time we've seen weather like this?"

University of South Carolina researcher Cary Mock, geography, can supply the answer.

"The drought and this year's rainfall are certainly unusual for the last 100–150 years, but it isn't that unusual when you go back 300 or more years," Mock said.

In other words, this summer's rainfall is merely a drop in the proverbial rain bucket.

By midyear, South Carolina had received nearly double the rainfall in 2003 that it received during all of 2002.

Such a dramatic turn from drought isn't unprecedented though, says Mock, who in 2001 began to recreate South Carolina's severe weather and climate history.

Mock says records show some huge floods helped end a severe and prolonged drought that gripped the Palmetto State during the 1840s and 1850s.

Using newspapers, old instrumental weather records, personal diaries, plantation records, and ship logs, he has documented the state's weather back to the 1730s. Tree-ring data also provide clues on rainfall and drought. Mock's work complements data collected by the National Weather Service which, since it was established in the mid 1890s has given climatologists and other researchers valuable longitudinal data for forecasting.

"In late August 1852, rain from the Great Mobile Hurricane swept through from Alabama, causing a huge flood of the Congaree River," said Mock, who revealed that the state was at least 8 inches below normal rainfall levels by that time in the drought. "In fact, that event ranks among the top five floods for that river."

A similar drought occurred a century earlier. Tree rings helped substantiate the severity, said Mock, who emphasizes that the only clear cycles that researchers recognize are night and day and year to year.

"However, that doesn't mean data don't reveal the probability of certain weather events occurring," he said.

South Carolina's weather history is fascinating, and rain is no exception. Besides total accumulation, rain also can be measured in number of rain days. Take 1796, for instance. In January of that year, 16 days of rain were reported in Camden by James Kershaw, leading to the Great Yazoo Freshet that impacted the Midlands, the Upstate, and Augusta, Ga. (Freshet is an older term for flood.) The remnants of a strong hurricane from Georgia caused a similar freshet in the Upstate in 1824, said Mock, who teaches courses in climatology, meteorology, and paleoclimatology.

In his research, Mock has uncovered other fascinating precipitation facts:

• Back-to-back record-cold January temperatures in 1856 and 1857 and more than a foot of snow in many locations. The temperatures, which were mostly below freezing and at times below 10 degrees in the Midlands, were far more severe than 1940 and 1977, two harsh winters still remembered today.
  
• The late-spring killing frosts of 1828 and 1849. In April of these years, South Carolina had severe frosts that destroyed vast areas of cotton and other plants. The frost in 1849 was accompanied by unusually heavy snow, which reached 6–8 inches in Columbia.
  
• A coastal snowstorm in 1800 that dumped 8 inches of snow in Charleston and a frigid early February in 1935 that brought temperatures near zero in Georgetown and Charleston and below zero in Columbia, killing orange trees.
  
• An early-fall killing frost in October 1789 that had a serious impact on South Carolina, particularly Charleston.
  

Hurricanes have their own detailed history. Mock has created a continuous record of hurricane activity back to 1778, with some information dating to the late 1600s. His findings suggest that the hurricane of 1752 was perhaps the strongest in the state's history, and that 1838 has the distinction of having the most landfalling South Carolina tropical cyclones (four) in a single year.

As if reaching through time, clergy, physicians, and plantation owners have befriended Mock, revealing weather history in their personal accounts and written observations. Among the noted diarists were Samuel Porcher Gaillard from Sumter, Henry Ravenel from Aiken and St. John's, William and Jasper Bartell from Marion County, and Daniel Cannon Webb from Charleston. Some people took detailed instrumental readings, including John Lining of Charleston, the Rev. Alexander Glennie of Pawleys Island, James Kershaw of Camden, various doctors at the Charleston Board of Health, an unnamed Columbia observer, and soldiers at Ft. Moultrie. Interestingly, thermometers—
not rain gauges—were commonplace early on. Few people used rain gauges until the 1840s.

Mock says more instrumentation and documentation came about because of heightened health concerns, such as the fear of yellow fever. Yellow fever epidemics in Charleston in 1858 and 1878 were particularly severe. A warm winter, which is conducive to higher mosquito populations, preceded each, with 1878 having an El Niño year that rivaled in magnitude the one recently experienced in 1997–98.

As Mock continues to build his weather history of South Carolina, he hopes his research will take him to London, where an untapped resource of ships logs of the Royal Navy dating back to 1720 lie waiting. Mock says Royal Navy ships would dock in Charleston for three years at a time, with ship officers required to keep detailed records.

08/03