I work in the middle atmosphere and several things in this article I disagree with. First off, the polar vortex is a stratospheric and mesospheric jet stream that exists in the winter time. There is no polar vortex in the stratosphere during the summer. Let me repeat that. There is no polar vortex in the northern hemisphere right now! So how are you using it for predictions? Second, the media stole the term “polar vortex” for the Arctic jet stream that exists in the troposphere. Moreover, while correlations have been made (see Baldwin et al., 2021) on the stratospheric impact on the tropospheric weather, the physics aren’t well understood. Assuming you can make predictions on the northern hemisphere winter based on the polar vortex in the stratosphere (which again, doesn’t exist yet because it is summer) months out is unlikely.
Edit: I edited out the argument that the OP may not reputable since they are a meteorologist in Canada.
Edit2: I’ve edited my original post slightly after discussing this concept with the OP.