This winter, there will be a new racing series taking place. This will be the Ribble Winter Racing Series.
The series beings on the 3rd of November and runs through the 23rd of March. The series takes place during peak Zwift season, so expect a high attendances rate at this race series. Unfortunately, the race only has one time zone, 11 AM PDT(7 PM for those in the UK).

There will be a Zwift Power league with prizes for the top riders and for riders who improve the most. To keep track of that league, head over to this page: https://zwiftpower.com/league.php?id=1272. Like most races nowaday, category enforcement is being used in this event.
To sign up for these events, head over to this page: https://zwift.com/events/tag/ribble. The page will display all upcoming races in this series.