Comparison of in situ observations at Earth and modelled velocity (top panel) and density time series (bottom panel) obtained in EUHFORIA simulations, for the cases of the Earth, at zero degree longitude and latitude, for Event 2. The in situ data are presented as the green line and the modelled time series have different line styles according to the fitting that they present. We also include with the blue curve the results for Earth, for the case of the DONKI parameters. The modelling results were obtained using the CME characteristics obtained from the fittings that we obtained with the GCS technique. The red arrow indicates the observed arrival time at Earth. The blue arrow indicates the estimated arrival time from the measurements of the radio observations. The modelled arrival times of the shock waves at Earth are at earlier times at first but they gradually shift towards the observed one as the fittings are done for times that the CME is further from the solar surface. The observed Δt is different for different fittings, ranging from 2–18 h.