Next generation LEO/GEO atmospheric sounding instruments should be capable of providing near-continuous high spatial resolution atmospheric temperature and humidity soundings on both global and regional scales. Global measurements are important for producing extended range forecasts of synoptic scale weather patterns and providing the boundary conditions for regional mesoscale models designed to provide warnings of localized intense storms. Experimental forecast system results indicate that the temperature and moisture measurements should be with high-spatial (2 to 8-km) and temporal (30 to 120 min) resolution to resolve the thermodynamic (i.e., atmospheric stability) and dynamic (i.e., horizontal, and vertical motions) processes responsible for global environmental conditions and localized severe weather. This paper provides a synopsis of expected improvements in global Numerical Weather Prediction (NWP) weather forecasts initialized using vertical atmospheric profiles retrieved from a combination of currently operational polar and geostationary satellite data, which simulate the sounding capabilities of next generation satellite sounding systems.