San Luis is indeed a great place for landlocked stripers with some big fish reportedly caught there. I don't recall (or haven't seen) the warning lights, but I can confirm from experience that the winds get up in the afternoon and the lake can get quite choppy. I wouldn't call them near-ocean condtions, but it's all relative and, when you're in a small boat, small waves can appear huge. When we got caught outside the Golden Gate in seas that reached 28 feet that afternoon (weather man got the forecast wrong), I would have given anything to be on San Luis.
I haven't fished San Luis for a number of years but I recall seeing RVs parked at the shoreline when we used to trailer a boat to the reservoir and often thought it would be a neat place to spend a weekend.
Patiently waiting for a photo of your big striper ;D