Geospatial Analysis of Monsoon Precipitation Data from Citizen Reporters
Half of annual precipitation in southern Arizona falls in convective thunderstorms associated with the North American Monsoon season (June 15 - September 30). Monsoon precipitation varies widely over distances equal to or smaller than the spacing of institutional rain gauges and the resolution of precipitation raster products. A more detailed spatial characterization of monsoon precipitation data is desirable for emergency responders and flood planners. Denser point precipitation data for Arizona are available through the Rainlog citizen rain gauge network. A geospatial comparison of these data to institutional rain gauge data and a widely-used raster dataset was conducted using open-source tools to determine the fitness of Rainlog data for direct comparison with institutional data. Despite key differences in the datasets, the Rainlog data were found to represent a valuable supplement to institutional data that can be merged with institutional datasets for analysis.