It's a better way to phrase it, certainly, but that wasn't my question. I've heard reporters use the original phrasing (i.e. "threatened Saturday"), so I consider it correct, just with incorrect punctuation. I was trying to figure out what the proper punctuation would be without changing the words.

This is part of a more general problem I have with being able to write the way I speak. I don't think I have terrible grammar when writing something relatively formal, in a "written tone" rather than a "spoken tone", but when I make comments on reddit or HN, I've noticed I have a general inability to also make my writing grammatically correct. I also use a lot of parentheses, because I tend to talk in tangents, and that's the only way I can really write it that makes sense.

It was an intellectual curiosity, nothing more.