The Local Analysis and Prediction System (LAPS), run by the NOAA's Forecast Systems Laboratory (FSL), combines numerous observed meteorological data sets into a collection of atmospheric analyses. LAPS analyses data include hourly three-dimensional and surface distributions of temperature, surface u and v winds, vertical velocity, dew-point temperature, relative humidity, specific humidity, ... pressure, MSL pressure, cloud type, mean cloud drop diameter, cloud base, cloud top, fractional cloud cover, cloud liquid water, cloud ice, surface precipitation type, rain concentration, snow concentration, soil moisture, snow accumulation, snow water equivalent, and snowmelt over the Cold Land Processes Experiment (CLPX) study areas in Colorado and Wyoming, USA (approximately 36.1Â°N through 45.8Â°N latitude, and 113.8Â°W through 97.2Â°W longitude). The CLPX LAPS analyses archive spans the period 1 September 2001 through 31 August 2003. Data are separated into a 2-D surface field group and a 3-D upper air group. Data are available at an hourly resolution on a 10-km horizontal grid (125 x 105), with the 3-D upper air group comprising 21 vertical levels. All data files are delivered in netCDF format.