The fourth edition of this bestselling book explains how to combine professional weather forecasts with information from self-assessment of the signs in the sky, as well as from websites and apps, to arrive at a local forecast of coming weather. The Weather Handbook is the essential guide to how the weather is formed, providing readers with the ability to look at the sky and interpret its signs. This handbook has been the standard reference for over 20 years for skippers and crews of cruising and racing yachts. The fourth edition has been updated and expanded with new photos and explanatory text, addressing new sources of weather information. There are countless websites and apps providing forecast data, and The Weather Handbook guides users in how to use and interpret this information for themselves, taking a general forecast for a wide area to provide a local forecast for a specific location.