The tropics are awake. Tropical Storm Iselle, the first named eastern-Pacific storm to matter for us this season, is pushing a south swell toward Southern California mid-week. It is not a giant - the forecast is a modest mid-period pulse, roughly chest-to-head-high at exposed south-facing breaks, building Tuesday, peaking Wednesday, and easing Thursday - but even a modest south swell changes where and how you should dive.