Hearing the murmurs, Harriet and I asked for a weather forecast for our Dolphin 460 cat, OCEAN, from Commanders’ Weather, a passage-routing service we’ve been using for the past 10 years. The meteorologists replied with a picture of, well, a whole lot of stuff going on in this pocket of the Pacific. Along our route we’d also be downloading weather GRIBs from PredictWind; the updates are easy, and the weather-routing simulations help us grasp the dynamics of ocean weather.
This passage is likely to be a mash-up of three parts, though the weather elements of each part can expand, contract, intensify, or fizzle out – this is what happens when weather elements meet and mix. In part one of the passage,of the winds begins: the calms and squalls of the Intertropical Convergence Zone (ITCZ) wander drunkenly about in a zone hundreds of miles wide between the northeast trade winds and the southeast trade winds. Finally, in the third and longest leg of the passage, about 500 miles, cruisers often face 10- to 20-knot headwinds and chop from the southwest. And the currents of this passage are variable, too. Does this sound tricky to predict? It is.
