Sudden squalls in San Diego are exceedingly rare. The open ocean is not usually too rough, except in storms. Other than surf launching and landing from the beach, which I almost never do, the worst conditions to be found in San Diego waters are for about 50 yards before and beyond the channel entrance. Even when the lifeguard report for the channel is "rough for navigation", the open ocean is often not that bad. When the lifeguards report "hazardous for navigation" or "closed to navigation", the channel should be avoided. However, the lifeguard report does not generally mention swell period; the NOAA report is required for that.
I have been transiting the channel for perhaps 25 years, once or twice a month, and regularly get the lifeguard report. Only recently I started getting the NOAA report including wave period, but I don't know what to do with that info. I also don't know what to do with barometric pressure.