SAILING THE WORLD

Dick Beaumont spells out what you won’t find in the almanac

- Dick Beaumont

Passages and their planning consist of the three Ds: departure, duration and destination, but they must include the factors mentioned under voyage planning: understanding currents, and a long-term overview of wind trends. It’s important to bear in mind the general wind trend if the passage is five days or over, because though the specific forecast may deviate from the prevailing, or expected pattern, there will be a high probability it will revert to the norm at some point during the passage...

PART TWO

Passage planning

Weather

Wind pilots provide a pattern of wind direction, but they are a historic record of wind direction and strength. They are by no means a forecast.

In recent years I have noticed much greater variations from the wind pilot’s historic data, as global warming affects the world’s climate, a factor that therefore needs to be borne in mind.

We now need to consider weather forecast charts, to see how the weather systems impacting our passage are moving, and their strengths and directions.

Start looking at the weather charts 10-14 days before departure to get a feel of how the weather systems are developing, then plan an intended route a day or two before actual departure. As the passage progresses, check the weather charts daily and modify the route accordingly to take account of forecast changes.

It’s important to remember it is a forecast not a guarantee of weather to come. It will not show very local weather variations, such as small intense thunderstorms, so be wary especially in the tropics. A squally thunderstorm can creep up on you, suddenly increasing winds from five to 40 knots in just minutes, then be gone again 20 minutes later. If you get caught with your cruising chute up you will get it down again but perhaps in more than one piece.