I was wondering about that! Several of the sites I went to referred to 3-ply yarn as being “fine”, but I was pretty sure this pattern was calling for a heavy weight yarn. It is confusing : )
Interestingly the Ravelry adaptation calls for worsted yarn, but the recommended yarn is listed separately from the worsted weight. Like what you both have said, I think it might be closer to bulky but would need to do a swatch first.
The pattern is a modification of the Children’s Tomten Jacket. I have her book “Knitting Without Tears”, but found it done with some modifications by Jared Flood. There’s quite a few changes, but I really like the finished result, and would really like to try it. I have a family member who is very in to Tolkien, and this reminds me of something from one of his books.
There is a gallery on flickr as well as two posts on the modifications.
Adult Tomten Jacket