It also says: "There, a possible mechanism is that evaporation might be enhanced by strong winds induced by convective updrafts and downdrafts [cf. Redelsperger et al. 2000] and might thus contribute to the positive RH anomaly on days with convective activity (see section 3.2)."
Am looking at weather for San Felipe for Sat 5 Oct 2019 for 16:00. It says 31 deg C and RH=36% Was reading https://agupubs.onlinelibrary.wiley.com/
Now if you use a sheet of steel (or perhaps a flat hydrogen blimp) to deflect wind into the almost saturated air just above the sea surface you will decrease the RH at the surface which satisfies condition 1. In fact my evaporation equations tell me that decreasing RH from 80% to 70% could lead to about a 40% increase in evaporation. Increasing evaporation will lead to regions of air with higher relative humidity than the surrounding air. Since this air is lighter than less humid air at the same temperature you will have convection which satisfies condition 2. Also water vapour is a greenhouse gas and is heated by infrared radiation from the sea (and a little by direct sunlight since the CO2 and water vapour collectively absorb radiation of between about 0.82 and 3.2 microns in wavelength). Again this satisfies condition 2.
So it appears that placing wind deflecting sheets in the Gulf of California at strategic intervals could enhance rainfall by differences in RH and convection. Perhaps not likely at present, but possibly a future setup to enhance rain chances for the Salton Sea.
One could also use the device below to deflect drier air down to the sea surface.
