A relational modeling framework is presented for representing a class of uncertain hybrid dynamical systems exhibiting delayed, infrequent, and uncertain observations. The model defines ranges of possible state evolution, and consequently the system trajectories corresponding to a given observation sequence are typically nonunique. For monitoring and state estimation, it is infeasible to individually track each of the potentially infinite number of possible trajectories. This paper presents a method of encoding a family of trajectories in a graphical representation. Necessary and sufficient conditions are given for the existence of a finite encoding of system trajectories corresponding to received observation sequences.