It is very safe to say that when it is raining, especially heavily, that SFO
will use the 10s. This is a regular practice during the winter wet months. Landing on the 10s is more uncommon than departures. I guess when the rain rolls in, the wind shifts to the south and makes the 10s a better runway for departure.
will use the 28s even if there is a southerly wind but only if it is dry. One time while listening to my scanner, a controller said that the airport procuders require them to use the 10s and 19s when it rains because the runways were too wet with a cross wind. So if I interpret this right, its OK
to use the 28s and 1s with a cross wind, but only when dry.
However, TACA is a regular user of the 10s. I often hear them request to depart using the 10s even during the summer while most traffic is using the 28s and 1s for landing and take off. I guess they want to save fuel so they don't have to make that long left turn over the city after departure. Immediately after take off, they make a hard left turn to avoid traffic on base and final. But its kinda funny because the taxi from terminal A, the one TACA uses, is at the other end of the airport. And when they use the 10s, they often have to hold short of the runway for along time so ATC can make hole for them in the traffic flow. I would think with this long taxi and holding, they would use just as much fuel up.