here you have many cameras in tarifa http://www.spotfav.com/
also do not pay much attention to the forecast (well, you have but...) here in spain we call the winds
levante and poniente (it refers to where the sun comes, dawn, and where it go, dusk)
generally levante winds are very strong and gusty (if the forescast expect 20 you may get 30..or at least 20 with gust of 30) and this levante is dry and hot.
in the other hand poniente usually is more constant, but also cooler (but in may is no problem)
hope you have good winds!