Columbia River - Grassy Island Rainfall ForecastUnited StatesORClatsop CountyColumbia River - Grassy IslandToday 16 AprNo RainThu 17 AprNo RainFri 18 Apr10%Sat 19 Apr20%Sun 20 Apr55%Mon 21 Apr20%Tue 22 Apr5%Columbia River - Grassy Island rainfall forecast issued today at 11:04 am. Next forecast at approx. 1:04 am.1-Day3-Day5-Day Graph Plots Open in Graphs Rainfall Probability Forecast NOAA Rain Today Real-Time Portland RadarNational SatelliteNational SynopticGet WillyWeather+ to remove ads