Climatological Evaluation on Extreme Precipitation in Florida

Florida is considered one of the wettest states in the United States, receiving at least 50 inches of rain annually. Due to the topography and geographical location, excessive precipitation could lead to flooding, causing damage to communities, agriculture, and ecological systems. Despite its importance, current climate projections cannot accurately predict precipitation variables. Understanding the climatological pattern of precipitation extremes across the state could improve meteorological and hydrological forecasting and, in turn, water resource management. This study used observational data from the Florida Automated Weather Network (FAWN) to assess the diverse hydrological systems across the state. One station was selected in each of Florida’s five water management districts (SFWMD, SWFWMD, SJRWMD, SRWMD, and NWFWMD) to analyze hydrometeorological trends statewide. The five stations selected for analysis were Quincy, Live Oak, Pierson, Dover, and Homestead. Twenty years of daily 2m mean temperature and total precipitation data between 2003-2022 were evaluated. Initially, tests were made to assess the correlation coefficient between NCEP-NCAR Reanalysis 1 data and the observational data to verify if reanalysis could be used for this study. However, the weak correlation between the two datasets for the daily precipitation highlighted limitations in the use of reanalysis data for hydrologic variables. The 2m mean temperature was similarly investigated to identify whether this variable would also present a problematic correlation, and as a result, a strong correlation was obtained. After these initial investigations, only observational data were used to assess Florida’s climatological trends for precipitation, and to present coherence in the analysis, the same methodology was applied for temperature. Mann-Kendall tests assessed trends for precipitation, temperature, and extreme precipitation events. The results demonstrated that during the 20-year period, a significant increasing trend for daily precipitation and temperatures was observed. The rising trend for daily precipitation can have negative implications for the environment. However, no trend for extreme precipitation events was identified in the state due to the irregularity of the precipitation variable. It is recommended that future studies be carried out to investigate further the use of reanalysis data for precipitation and extreme events.