The observations in mid-latitudes are consistent with those in high latitudes. The ground-based geomagnetic observations from mid-latitude stations show that the magnetosphere was much quieter on May 11 than on May 14. The data from three stations in IGPP/LANL magnetometer array are shown in Figure 4 including Air Force Academy site (AFA, MLat: 48.1 N) in Colorado, Los Alamos site (LAL, Mlat: 44.6 N) in New Mexico, and San Gabriel Dam site (SGD, 40.7 N) in California. Local noon is at 19 UT at AFA and LAL and 20 UT at SGD. On May 14, there was enhanced power in Pc 3-4 band throughout the dayside hours at all three stations. As expected, the wave power was strongest at the higher latitude station AFA. However, Pc 3-4 waves were completely absent at the two lower latitude stations, LAL and SGD, on May 11. At AFA, some isolated pulses of Pc 3-4 waves are present in the dayside but the wave power was much smaller in comparison with those on May 14.