The GPM Ground Validation KLGX NEXRAD OLYMPEX dataset contains data from selected NEXt Generation Weather RADar system (NEXRAD) instruments in operation during the Olympic Mountains Experiment (OLYMPEX) field campaign to help support the ground validation of the Global Precipitation Measurement (GPM). NEXRAD is a network of 160 stationary S-Band radars dispersed throughout the United States and select locations abroad. Datasets gathered from three NEXRAD stations, as listed below, extend from 22 September 2015 through 01 May 2016 as part of the GPM Ground Validation OLYMPEX data. This dataset contain browse images of base reflectivity observations in the Portable Network Graphic (PNG) format. Base radar reflectivity is the measure of transmitted power returned to the radar after intercepting a target, for example, rain droplets. This information can illustrate the amount and size distribution of water particles in a given unit volume of atmosphere.