Calculations of the magnetic shadow zones of lunar-based particle detectors are extended to include the effects of local remanent magnetic fields. At the Apollo 14 site the local magnetic field is approximated as that of a dipole. Numerically calculated open and shadowed zones are shown to be in agreement with quiet time plasma sheet observations of the charged particle lunar environment experiment. An analysis of three storm time observations indicates that magnetic shadowing can significantly alter the near-lunar-surface electrostatic potential distribution.