I use MyWindsock pretty extensively, but the main thing is once you've done a bunch of races then you can get a rough range of its estimated CdA. Don't take any stock in the actual value but if similar distance and traffic levels to your event then you can plug in those ranges and what power you think you can hold (again I do a low and high). This will give you a target speed for the 'fast' and 'slow' bits for the course.
Given it takes into account the elevation profile and the weather on the day, it's been a great guide to pacing. Personally find it much easier to try and maintain a speed for a given segment, rather than monitoring power constantly.
I use MyWindsock pretty extensively, but the main thing is once you've done a bunch of races then you can get a rough range of its estimated CdA. Don't take any stock in the actual value but if similar distance and traffic levels to your event then you can plug in those ranges and what power you think you can hold (again I do a low and high). This will give you a target speed for the 'fast' and 'slow' bits for the course.
Given it takes into account the elevation profile and the weather on the day, it's been a great guide to pacing. Personally find it much easier to try and maintain a speed for a given segment, rather than monitoring power constantly.