The insulater is no more and the postitve charges in the object are very strongly attracted to the negitive charges at the base of the cloud. It's at this point the fireworks start to happen. The positive charges in fact jump up to the cloud from objects below. The negative charges do not go down to the object. This act is known as lightning.
Lightning usually carries thousands and thounds of amps of energy.
This usually happens in a fraction of a second. Copyright 1998 by N2H2, Inc.