The emergence of phasor measurement units (PMUs) coupled with GPS time devices makes it feasible to directly compare timestamped measurements collected at different locations without needing to account for clock drift. GridStat is a flexible publish-subscribe status dissemination middleware framework with capabilities that include rate-filtered multicast for each subscription. In this paper we explore GridStat's ability to hide the complexities of distributed systems from application developers while efficiently providing time-synchronous groups of PMU data from physically disparate locations.