Comparison of in situ observations at Earth and modelled velocity (top panel) and density time series (bottom panel) obtained in EUHFORIA simulations for Event 2. The in situ data are presented with the green line and the modelled time series have different shades according to the positions at which they were estimated (see also Fig. 2a). The modelling results were obtained using as inputs the CME characteristics obtained from the DONKI database. The red arrow indicates the observed arrival time at Earth. The black arrow indicates the modelled arrival time of the shock wave at Earth (dashed black curve) at zero degree latitude and longitude. The blue arrow indicates the estimated arrival time, employing the drift rate of the type II radio bursts. The modelled arrival time of the shock wave at Earth is significantly earlier than the observed one, Δt ≈ –12 h. The observed Δt is different for different latitudes, ranging from 7–12 h.