We develop a model of interruptible electric power service that includes early notification. Notification time is included through a multi-period model. The allocation of notifications is described as a stochastic control problem: whom to notify when. The general problem has great information requirements and an optimal allocation may not yield an incentive compatible price menu. Additional structure is imposed on customer outage costs and the evolution of uncertainty in the shortfall magnitude. Optimal priority orderings are sought. Optimality conditions and qualitative properties are derived. A numerical example illustrates the results.