Solar wind dynamic pressure and interplanetary magnetic field (Z component in GSM coordinates) measured by Wind spacecraft, SYM-H and AE indices measured at ground. Dashed lines mark an area that we can relate from Wind to ground that corresponds to an enhancement of P_d and SYM-H, the delay is due to their different locations. Dash-dotted line marks when B_z becomes negative suddenly and then the main phase of the magnetic storm starts, AE suddenly increases.