This first part of the dataset contains the atmospheric and surface conditions of Halifax test scene (39316D) used for pre-launch studies of EarthCARE’s retrieval algorithms and data management system. The data are produced by Environment and Climate Change Canada's Global Environmental Multi-scale (GEM) NWP model (Côté et al., 1998, Girard et al., 2014). The surface albedo climatology is based MODIS’s MCD43GF 1 km resolution bidirectional reflectance distribution function (BRDF) product for the period from 2002 to 2013 (Schaaf et al. 2002). Please refer to the second part of this dataset for the hydrometeor and aerosol properties. The Halifax test frame is 6200 km long and 200 km wide with horizontal grid-spacing of 250 km and 57 vertical layers. The simulation is initiated at 12h00 UTC on 07-Dec-2014 and saved at 17h30 UTC. This frame extends from southern Greenland, across extreme eastern Canada, and ends in the Atlantic Ocean roughly 500 km north of Dominican Republic. It includes night time over Greenland, cold surface air over eastern Canada, a cold-front with deep clouds just off the coast of Nova Scotia, and scattered shallow clouds between Bermuda and Dominican Republic.