Maybe a broken solder joint at the BNC connector.
I was going to say the same thing.
If the WX broadcasts aren't being heard, then the receiver just isn't picking up any signal at all. The OP should get the local WX station even with the Rat Shack 800MHz antenna!
To the OP, another seemingly dumb question, but by any chance, do you have a habit of picking up the radio by the antenna?
You would be surprised how many people do that with HTs of all kinds, including a few knowledgeable hams I know!
If so, that could have caused the solder joint of the antenna connector to break, as "signal500" suggested.