We are delighted to announce that we will start an online series of open seminars and discussions starting in June 2021 to address the grand challenge of predicting harmful algal blooms. This monthly series will be delivered by six experts and the topics will cover size-based models, acclimation models, model validation, and machine learning etc. The participants will have the opportunity to share their local issues with the community, to interact with leading scientists in the field, and to learn state-of-art modelling techniques. We will also host a set of Slack channels to facilitate both online and offline discussions. This webinar series will serve as a precursor for a week-long, in-person GlobalHAB workshop (sponsored by EuroMarine, and US NOAA) that will take place in Glasgow, United Kingdom in the Spring of 2022. The webinar series is free and open to all, but a one-time pre-registration is required. For access to the webinar links and discussion forums, you will need to join the HAB Modelling and Prediction slack site. For any enquiries, please contact Bingzhang Chen via Bingzhang.chen@strath.ac.uk.