What is already known:
What this study adds:
Flash flooding can cause hundreds of deaths and billions of dollars worth of damage each year. In 2015, there were 176 fatalities in the United States, Puerto Rico, Guam and Virgin Islands, which is roughly five times higher compared to those caused by tornadoes. The Multi-Radar Multi-Sensor (MRMS) system, which generates a 1-km grid of quantitative precipitation estimates (QPE), can provide insight to forecasters when issuing flash flood warnings. The most accurate data are needed for the high spatial resolution of MRMS. Rain gauges are treated as ground truth and can provide the most accurate verification of QPE. The most well-known gauge network is the 838 rain gauges from Automated Surface Observing System (ASOS) stations. It is a standard to accept that QPE values can vary from collocated observed gauge values however, location errors of the rain gauge can have an impact on the verification of MRMS QPE. Using Google Earth, it is determined that ASOS location errors varied from less than 3 m to 80,163 m. The locations errors resulted in 79.31% of ASOS stations in the CONUS to be in a different MRMS QPE grid box. Of those stations, 19.44% were found more than 1 km away from the expected locations. QPE values for the new and old locations were compared to observed precipitation data with the correlation increasing from 0.777 to 0.810. This comparison highlights the need to update rain gauge metadata to improve the verification of radar-based QPE and other hydrometeorological products.