The New Jersey Geological and Water Survey (NJGWS) developed a set of daily naturalized stream flows for the surface water supply reservoir systems in the Passaic, Hackensack, and Raritan River basins of central and northeastern New Jersey. The naturalized flows have been developed for the October 1,1921 through September30, 2019 period. Naturalized means that the hydrologic modifications caused by the existence and operation of the reservoir systems have been removed from the observed stream flows. This allows for the simulation of today's infrastructure and regulations with historic unimpacted or "natural" hydrology. The naturalized flows were utilized in a RiverWare model of the reservoir systems in hindcast mode to develop a set of storage volume guide curves for drought management. The RiverWare model is also being run in forecast mode using ensembles of the daily naturalized stream flows divided into one-year or multi-year forecast periods. A one-year forecast period with a 97-member ensemble is used for normal drought monitoring and management. Four-year and eight-year forecast periods have been used to assist with a multi-year infrastructure improvement project. Non-exceedance statistics are applied to the forecast run outputs to generate graphs of the probabilities that reservoir system storages will be above or below the guide curves over the forecast periods. The forecast probabilities provide advance insight into the likelihood of crossing the guide curves and provide additional time for drought management decision making. Outcomes include improved drought management decision making and increased water supply reliability for New Jersey.