A Quantitative Comparison of Precipitation Observations as Measured by the COOP, ASOS and Kentucky Mesonet Networks

This study presents a comprehensive and quantitative comparison of precipitation data collected from three statewide, in situ weather observation networks: the Kentucky Mesonet, the Cooperative Observer program (COOP) and the Automated Surface Observing System (ASOS) network. This work assesses the strengths and limitations of each network through identification of biases or discrepancies in the historical records peculiar to each network. Daily precipitation records from the Kentucky Mesonet for the years 2011 to 2020 will be compared with nearby (within 25 km) COOP and ASOS stations. Using simple statistical analyses such as mean, root mean square error, variance, t-test and Pearson correlation, differences between networks will be quantified and investigated in light of network differences in siting characteristics, instrumentation, and quality control. Data extremes will also be evaluated due to overreporting or underreporting as a result of instrumentation. This is the first of such comparison and results may allow for a more accurate historical record to be developed of the climate across the Commonwealth. In addition, this study will allow for a deeper understanding of the reliability and consistency of these reporting weather observing networks, thereby contributing valuable information to meteorologists, climatologists, and researchers involved in climate studies, impact assessments, and policy formulation.