Grayrocks Reservoir Rainfall ForecastUnited StatesWYPlatte CountyGrayrocks ReservoirToday 19 Apr15%Sun 20 Apr10%Mon 21 Apr25%Tue 22 Apr10%Wed 23 Apr40%Thu 24 Apr50%Fri 25 Apr50%Grayrocks Reservoir rainfall forecast issued today at 3:04 pm. Next forecast at approx. 5:04 am.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast NOAA Rain Today Real-Time Cheyenne RadarNational SatelliteNational SynopticGet WillyWeather+ to remove ads