Thermodynamic properties of the troposphere, particularly water vapor content and temperature, change in response to physical mechanisms, including frictional drag, evaporation, transpiration, heat transfer, pollutant emission and flow modification due to terrain. The planetary boundary layer (PBL) is characterized by a greater rate of change in the thermodynamic state of the atmosphere than at higher altitudes in the troposphere. Measurement of these changes, such as large horizontal gradients in water vapor and vertical profiles, provides very important data for improved weather prediction. Sensitivity studies for severe storm prediction indicate that a lack of accurate observations of water vapor densities throughout the lower troposphere limits the forecasting of severe storms. Therefore, measurements of water vapor density using microwave radiometers may help to improve accuracy of severe weather prediction. The HUMidity EXperiment 2011 (HUMEX11) was conducted to validate remote sensing of tropospheric humidity using ground-based scanning Compact Microwave Radiometers for Humidity profiling (CMR-H). A network of microwave radiometers was deployed to measure an atmospheric volume using various scanning patterns near the U.S. Department of Energy (DOE)'s Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Climate Research Facility. Scientific objectives of HUMEX11 included the measurement of water vapor profiles in the lower troposphere with high vertical and temporal resolution.