Weather is a very important thing to a sailor, and knowing the weather ahead of time can allow you to better prepare for the weather to be. There are fancy electronic methods to predict the weather, allowing you to tap into a world of information.
Weather can be found online on your smart phone via websites and apps, or over the radio on the various NOAA weather stations. When far out to sea, weather can still be received by SSB radio in the form of weather fax, creating a graphical display of the weather forecast.
These are all wonderful systems that will give you very precise information. The best part about these systems is the information is generated by experts in the field who fully understand and comprehend what the weather is doing now and going to be doing soon. The downside to all of these systems is that your boats electrical system could fail and you won't be able to receive this information.
Luckily, there is a very reliable backup system to receive weather forecasts; all you need to do is study the weather yourself a bit to gain an understanding of how the sky relates to the weather to be.
You are able to see clouds that are very far away, giving you a full day's warning to what is coming your way. Looking up at the sky will tell you everything you need to know about the weather around you in your immediate area and can be decoded to reveal what the future weather will hold for you as well.