Building Your Regatta Weather Forecast

by Jonathan McKee, Sailing World
One of the many great things about sailing is the ability to prepare in advance. The more you put into it, the more success you will have. Weather forecasting is one area that is increasingly being used by top sailors who once exclusively relied upon professional weather services. As the quality of available data and online resources has improved, along with sailors’ access to it, using the right information in the right way can be an important part of racing success. And it’s a fun part of getting ready for a regatta.

The importance of weather preparation varies greatly, however. For an ocean race or long passage, accurate forecasting — and using it correctly — can be the largest contributing factor for winning. On a Thursday night beer-can race, you are looking to decide what gear to wear or which headsails to leave on the dock. For the purposes of this article, I will focus on inshore course racing, where you will most likely have shoreline influences as well as meteorological effects.

To prepare for a weekend regatta at an out-of-town venue, the first thing I do is find historical data on the prevailing wind direction and speed for the month of the regatta. Next, I will study the geography of the racing area. Look at a chart showing the elevation of the shoreline and the underwater bathymetry. Determine where the higher terrain is, and where the deeper channels are. Speculate how these relate to the prevailing wind and current directions. Even without ever sailing in a place, you can get a pretty good idea of how the wind will bend around certain land features in ­different wind directions. There are a few good books on the topic of land effects, including “The Sailor’s Wind” by the late Stuart Walker. – Full report