Evolution of the vertical forces (positive values are in red and negative values in blue) at z = 24 Mm for t = 4.5 min, t = 4.96 min, t = 6.11 min, t = 7.63 min and t = 8.78 min. Panels a) to e) show the vertical component of the Lorentz force, f) to j) display the negative gas pressure gradient, k) to o) exhibit the net contribution of the Lorentz force and gas pressure gradient and panels p) to t) the advective component of the force. The magenta lines represent flux rope magnetic field lines, the darker (lighter) segments of the lines are above (below) the cutting plane. Grey contours indicate positive (solid) and negative (dashed) values of B_z at z = 0.05 Mm and the green contours exhibit different values of v_z between 218 (dark green) and 436 km s⁻¹ (light green).