This paper presents a coverage analysis for a dynamic coordinated beamforming for downlink satellite networks when modeling the spatial distribution of satellites and users using Poisson point processes on concentric spheres. Analytical expressions for the coverage probability conditioned on the normalized distance are derived in terms of the number of antennas per satellite, satellite density, Nakagami fading parameter, and path-loss exponent. Additionally, we obtain the average coverage probability by considering the distribution of normalized distances, thus validating the overall advantages of coordinated beamforming from a spatial average perspective. Our major finding is that coordinated beamforming offers superior benefits compared to the absence of satellite coordination in scenarios where the number of antennas on each satellite is large. Simulation results show the exactness of the derived expressions.