Extended Abstract (204K)17C.4
Reconstructing South Carolina tropical cyclones back to the mid eighteenth century
Cary J. Mock, University of South Carolina, Columbia, SC; and D. O. Mayes, J. Mojzisek, M. McWaters, and M. Chenoweth
Tropical cyclones are commonly recurring features in South Carolina. Examination of the modern tropical cyclone database (HURDAT, or Hurricane Reanalysis Project) since 1851, based on tropical storm centers within 85 nautical miles of Charleston SC, indicate significant tropical storm impacts on the region occurring about every 1.8-2 years, and at least category 1 hurricane impact about every 8-10 years. Major category 3 hurricane impact is evident for 1893, 1959, and 1989. We provide a detailed reconstruction at daily resolution back to the mid 1760s for tropical storms and minimal hurricanes, and back to 1752 for major hurricanes. A reanalysis was also conducted on the 1854, 1885, and 1893, currently documented in HURDAT as major hurricanes. Historical data consists of three different types: plantation diaries, early newspapers, and early instrumental records.
Plantation diaries provide constant information on an everyday basis and also detect weak tropical storms. Newspapers generally provide more detailed information on the intensity and damage from tropical cyclones than plantation diaries, but are generally better sources for stronger storms. Early instrumental records, such as from the Charleston Board of Health, generally contain brief verbal information but contain valuable information regarding barometric pressure, temperature, wind direction and intensity, and precipitation data. Results from our reconstruction provide new specific information on over 75 storms from 1752-1868. Temporal analysis of the tropical cyclone record, smoothed by a 5-year running average, indicate substantial decadal variability in the 1830s that is unprecedented in the modern record. In particular, 1837-1838 was the most active year for the entire period, with four tropical cyclones affecting South Carolina for each year. Return-intervals of minimal hurricane impact generally remained about the same as the twentieth century. Major hurricane impact is clearly evident for 1752, 1804, 1813, and 1822, suggesting highly anomalous behavior in major hurricane activity in the early nineteenth century. Analyses of the 1854 and 1885 hurricanes suggest that they were below major hurricane status over South Carolina, reinforcing the importance of critical examination of primary historical data. The approach used in this reconstruction offer a useful methodological framework for extending landfalling tropical storm reconstructions for other locations of the Atlantic and Gulf coasts, and for supplementing other data sources such as ship logs.
Session 17C, Tropical cyclone best track and climatology II
Friday, 7 May 2004, 10:15 AM-12:00 PM, Napoleon II Room
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