Rhos-y-llan Swell ForecastUnited KingdomWLGwyneddRhos-y-llan1-Day3-Day5-Day Graph Plots Open in Graphs Swell Height and Direction Forecast NOAA WaveWatch III Swell Period Forecast NOAA WaveWatch IIIRhos-y-llan swell forecast issued today at 12:48 am. Next forecast at approx. 12:48 am. Wave Height Sea TemperatureGet WillyWeather+ to remove ads