Optical monitoring data over several years in combination with the reconstructed 1-d response function for C IV obtained from the 1993 HST monitoring campaign of NGC 5548, reveal that: (a) radial motion does not dominate the gas kinematics (Korista et al. 1995); (b) line-profile variations occur in fixed regions of velocity space, a core and two wing components, are stochastic in nature, and appear to be unrelated to reverberation effects (Wanders & Peterson 1996). Wanders et al. (1995) showed that these variations are broadly consistent with a spherical BLR geometry populated with optically thick clouds following randomly inclined circular Keplerian orbits, and illuminated by an anisotropically emitting point source of ionizing continuum radiation. Here we provide a brief description of this model and summarize its basic properties. A more thorough analysis is presented in Goad & Wanders (1996).