Early in the 2011-12 JET ITER Like Wall (ILW) campaign, large tungsten (W) spikes were observed within 400ms after the X-point formation. The influx of W from the W divertor during this period can lead to significant changes on the evolution of the current profile and, in two extreme cases caused even disruptions. Although it was possible to reduce the occurrence of these events by 30% and minimize the impact on the plasma during the campaign, it is important to understand the physics behind the peaked W release and to find a way to avoid them in the first place. In this paper, EDGE2D/EIRENE is applied to reproduce this transition phase with strong W release and to compare it with experimental observations.