My business depends on the weather. I have been at the helm of sailing yachts roaming around the world in search of wind and waves on kitesurfing and surfing expeditions since 1999.
My passion is paragliding. This summer I set the North American foot launch distance record by flying 240 miles (386km) across the Continental Divide from Idaho deep into Montana. Most of that white-knuckle flight was made while running from a storm. I’ve made a life and a living out of interacting with weather.
In the movie Good Morning Vietnam Robin Williams's character offers a weather report by joking: “Got a window. Open it!” It's a good place to start but these days, there’s plenty of tools at our disposal that provide a dizzying mix of data. They key is how to interpret them. Getting it wrong can have dire consequences.
I was sailing our 60-foot (20m) catamaran solo from Bali to Malaysia one year across the equator through the Java Sea and Malacca Straits, the busiest shipping routes on Earth when a freakishly strong electrical storm swept across from Sumatra, a common, “unavoidable” occurrence at that time of year.
I hadn’t slept more than 20 minutes at a time in eight days. A raging infection that was playing havoc with my internal thermometer. Our instruments were malfunctioning so my autopilot would not properly steer the boat. When the storm hit I briefly lost control of the boat and a sheet (line) from the jib sail went overboard and got sucked into the prop.
My exhausted and clouded brain didn’t put up its usual alarm when I dove overboard, in the middle of the night, in zero visibility to free the line from the prop. If I had lost my grip the boat would have sailed away, stranding me, the conclusion of the story obvious.
Some practical knowledge of how bad weather develops is therefore a critical component of our outdoor tool-kit.
Get a barometer
At sea a barometer remains the second-most important tool I have on board (the first being my eyes). Any rapid and sustained (3-4 mb per hour, depending on your latitude) pressure drop means a serious low pressure system is approaching. Stand with your back to the wind, point your left arm out at 90 degrees and you’re pointing at the center of the approaching low, in the Northern Hemisphere (use your right hand in the Southern Hemisphere).
Look at the sky
The 500mb prognosis, or “winds aloft” forecast (typically about 18,000 feet) is a very good predictor of what’s heading our way on the ground.
Sustained, strong winds up high tells us that we’ve got the same coming on the ground 24 - 48 hours later. Ever look up into the sky and see wispy thin cirrus clouds, sometimes called “Mare’s tails”, as they resemble the tail of a horse? They mean winds aloft are strong. They are usually visible for just a few hours. In 24 to 48 hours you’re going to get some strong wind and likely precipitation as a cold front rolls in.
Being in a cyclone, hurricane or typhoon is terrifying but often easy to avoid, as they tend to congregate in certain places at certain times of year. Anyone who claims they were simply in the wrong place at the wrong time for something like a hurricane knows nothing about the weather.
My weather routine when I’m sailing or flying is always the same. I look at synoptic charts, long-range forecasts, instability prognoses. On land or at sea, we’re looking for the same things.
But to participate at some point you have to commit. Once you’re in the air or out at sea there’s not much more at your disposal than a good look around. Robin Williams was right. Got a window? Open it.