The GPM Ground Validation Doppler on Wheels (DOW) OLYMPEX V2 dataset was obtained by a dual-polarization and dual-frequency X-band mobile radar operated by the Center for Severe Weather Research (CSWR) during the Olympic Mountain Experiment (OLYMPEX) campaign. The DOW was deployed in the Chehalis Valley for the OLYMPEX field campaign with the goal of obtaining radar reflectivity and Doppler velocity observations in order to better understand the orographic enhancement of precipitation during frontal passages over mountain ranges. The DOW radar uses two 250 kW transmitters with a measurement range of roughly 60 km. These data are available in CFradial netCDF-4 format from November 6, 2015 through January 15, 2016.