Effects on Lift

This plot is found in "Effect of High-Fidelity Ice Accretion Simulations on the Performance of a Full-Scale Airfoil Model", Broeren, Bragg, et.al., 2008
This plot shows the angle of attack on the bottom axis, the coefficient of lift on the left axis, and the pitching moment coefficient on the right axis.  The lift profile is shown in the upper curves, and the pitching moment is shown in the lower curves.

Note: the pitching moment shown here is of the airfoil only, which is a part of the whole aircraft pitching moment.

Look at the area within the red box.

Will you notice any change in lift? At what angle of attack? Will there be any warning?

How does that relate to terms such as trace, light, or moderate ice?