The ability of a coronal mass ejection (CME) to disturb the near-Earth space environment is determined by its magnetic and dynamic properties, most importantly by the magnitude and duration of the southward interplanetary magnetic field component. However, current limitations with predicting solar wind parameters, in particular the magnetic field vectors in Earth-impacting CMEs, severely restrict the accuracy of long lead-time space weather forecasts. This introduces a significant problem since most space weather forecast end-users need reliable warnings at least half a day ahead with minimal false alarms.

This session aims at a synergy and discussion of methods, based on combining observations, theory and modeling for predicting CME magnetic and dynamic properties relevant for improving long lead-time space weather forecasts. This includes overcoming limitations in making adequate remote-sensing observations of key parameters and in addition, in estimating the deformation of the CME and changes in its geometrical parameters (due to rotation and deflection) during the coronal and interplanetary propagation. Papers focusing on estimating magnetic field vectors within CMEs with embedded flux ropes are particularly encouraged. We also highly welcome papers estimating the magnetic field and plasma properties within turbulent CME sheath regions, which may also have strong out-of-ecliptic magnetic fields, and hence, drive strong space weather storms.