i have a question. around what degree does the west in the sw swell become too much? like, if a true S swell is 180, is it around 185, 190? like, i imagine that short period swell filters in, but when does it become to the point where the direction really doesn't allow for it to show? i'm talking nj, btw.
I can answer for Delmarva and in some ways Delmarva is a lot like new jersey...the north sections face ENE, south section face more SE..
Its makes a lot of difference where you are forecasting for...on the delmarva the further south you go the more a SW swell gets in. In Delaware which faces ENE 180-190 will not show, in south ocean city which faces SE 180-190 will wrap in with a loss of height but still break ok.
Swell period matters a LOT. The longer the period with more the swell will bend in even if its steeply angled from the S. All steeply angled swell is basically wind swell but 8-9 second wind swell can bends in better than 7 second swell. Jetties tend to help these swells a lot by focusing a weak angled swell into peak.