Old River - Rock Slough Entrance Rainfall ForecastUnited StatesCAContra Costa CountyOld River - Rock Slough EntranceToday 19 AprNo RainSun 20 AprNo RainMon 21 AprNo RainTue 22 AprNo RainWed 23 AprNo RainThu 24 AprNo RainFri 25 Apr10%Old River - Rock Slough Entrance rainfall forecast issued today at 1:04 am. Next forecast at approx. 3:04 pm.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast NOAA Rain Today Real-Time Sacramento RadarNational SatelliteNational SynopticGet WillyWeather+ to remove ads