The el niño that everyone talks about (97-98 winter) happened while I was a ding-dong teenager (not that all teenagers are ding-dongs, but I sure was) so I didn't really care about its implications for me as a gardener, but I am thinking about the winter of 11-12, which was noticeably and abnormally warm here, and I managed to grow some stuff like turnips all winter without protection.
So I'm thinking if the predictions are for a strong el niño and that usually makes my region warmer and dryer, I might plant a bed of hardy greens and roots to grow over winter, and possibly plan on some minor protection and irrigation.
In our area from mid December 97 to mid September 98 it was dry (no rain at all) and hot, so we're preparing for exactly that. We're very concerned not to miss any rain water we can catch, mainly because we have no water lines and we fully depend on rainwater catchment from our roofs. Right now we have 8000 liters of water stored and we need about 40.000 more before mid December to make it through to September next year.
We're also delaying planting out areas we cannot irrigate and hope our dams will fill up so we can continue irrigating the lower areas for as long as possible. October and November are the wettest months here, so fingers crossed.
We know a past record is no guarantee for the same drought to happen again, but better safe than sorry.