A cruising sailor's best friend- The Weather Window

by Des Ryan on 11 Oct 2011 One of the main differences between racing and cruising, apart from the competitiveness or otherwise, is the constant use by cruising sailors of the concept of the Weather Window.

Most cruising, except for a few ocean crossings or a non-stop circumnavigation of something-or-other, is undertaken in passages that are rarely more than a week long.

So whereas the racing yacht must go when the gun goes, the cruising sailor has the greatest chance of travelling during clement weather, just by waiting.

Many of the difficulties encountered in racing, including the occasional fatal race like the 1979 Fastnet and the 1998 Hobart Race occurred because the sailors were racing in weather that would horrify an self-respecting cruising sailor. Had the crews racing had the luxury of being able to say 'No' when they read the weather forecast, many of them would not have departed.

But what exactly is a 'Weather Window'? Well, simply put, it is the time period of weather and sea conditions which are relatively suitable for the planned voyage. The weather window occurs usually between two periods of time when the weather is unsuitable, eg. sea state or winds would make an unpleasant, if not dangerous journey.

A fixed schedule is an anathema for a cruising sailor. Agreeing to collect visitors from a particular harbour on a particular day, or agreeing to deliver someone at a particular time to a particular place are agreements that the prudent sailor should avoid at all costs, as it may put the yacht and the crew in jeopardy if the weather conditions dictate that one should not sail.

For example, in temperate latitudes from the autumnal equinox right through to the vernal equinox in the spring, you can expect some king of weather disturbance every four days or so that lasts for 24 to 36 hours. So the sensible time for travelling, both for safety and for comfort, is between those disturbances.

The prudent sailor will be watching the weather patterns, the lows passing through, and the fronts, and will be standing by ready to go as soon as the disturbance has passed and the winds are favourable. Patience is the key, and the crew pressuring a skipper to go against his or her better judgement because 'I have to get back to work' or something similar, is the kind of pressure that good skippers will resist, and that good crew will never offer.

There are other kinds of weather windows apart from those experienced between systems passing. These are longer in their time frame and are more commonly referred to as seasons. Often these are the times when there are no hurricanes, typhoons or cyclones, dependent on where you sail.

At other times it refers to the prevailing winds. Travelling up the Red Sea, for instance, is usually undertaken between February and April, as these are the months when the south east winds extend furthest up the Red Sea, making the best of running with the wind while it lasts.

Rallies often make the most of the cruising season, occurring at the beginning or end. The Atlantic Rally for Cruisers (ARC) is a prime example of this, crossing the Atlantic from East to West at the beginning of the cruising season in November/December. This allows yachts from the Mediterranean region to spend the cruising season in the Caribbean. The return rally is timed for May, before the hurricane season begins in the Atlantic.

Similarly, the Port2Port Rally, from Port Vila in Vanuatu to the Port of Bundaberg in Australia occurs at the end of the cruising season in October, getting the yachts out of way of the cyclone season that afflicts the South Pacific from November on.

A skipper's weather and climate consciousness and his adherence to the use of weather windows is one of the greatest indicators of his or her good seamanship.