The shelf break frontal shape and the T-S relationships in the frontal vicinity have been observed to undergo a transition in the spring. It is shown that this transition should result from two simple assumptions: (1) during the early spring, the offshore density gradient becomes reversed in a layer of intermediate depth; and (2) the front is gravitationally stable. Observations south of Nantucket preceding and following the transition during 1979 illustrate the metamorphosis from a monotonically sloping front to a convoluted shape which delineates two layers of shelf water and two of slope water. The convoluted shape of both the front and the T-S curves after the transition are found to be consistent with the observed density gradients if it is further assumed that the front is Margules-type with a velocity discontinuity of 5 cm/s.