I had a question about differences in conditions during a particular swell - Some days, it seems that the ocean is firing - waves are constant, the paddle out can be really difficult and the currents moving around the water are very strong. Other days, you can paddle out without getting your hair wet, the water is very calm, and the waves primarily in sets every couple of minutes or so. The waves and forecast (winds, size, etc) during both of these days are the same - however, the conditions vary greatly. This happens quite often, for example a week or two ago during the Leslie swell. What causes this variation? Is there another variable that I am missing? Just curious for my own education.
Every swell system will vary, but the general trend of what you are describing is swells that are generated further away compared to storm systems that generate swells near the coast. Often, but not always, the longer wave periods will signify swells coming from storms further from the coast. Wind speed and wind fetch are also a determining factor in wave periods. In the distant storms, individual waves gather together in swell groups, where the faster swells groups travel faster then the slower swell groups.
How about when this occurs with a forecasted groundswell? Is that even possible with a storm that far out at sea?
Is what even possible? Ground swell is a term I don't like to use, because it doesn't really mean anything in particular. All swell eventually feel the "ground", but the longer the period the deeper the the wave will feel the ground. And, all coastal regions have varying bathymetry profiles. Instead, on Swellinfo, we use terms like short, medium, swell, long, extra long to describe the wave periods. As I mentioned above, the longer period waves, generally correlate with more distant storms.
