Ynys Gwylan-fawr Swell ForecastUnited KingdomWLGwyneddYnys Gwylan-fawr1-Day3-Day5-Day Graph Plots Open in Graphs Swell Height and Direction Forecast NOAA WaveWatch III Swell Period Forecast NOAA WaveWatch IIIYnys Gwylan-fawr swell forecast issued today at 12:51 pm. Next forecast at approx. 12:51 pm.Get an account to remove ads