There's another community post with 404 debugging tips that might be helpful. Please give these solutions a try and let us know how it goes.

https://community.vercel.com/t/debugging-404-errors/437

Vercel Community

Debugging 404 Errors

Sometimes things don’t go as expected when deploying a website. If you see a 404 on your site, that means the page or resource couldn’t be found. There are...

A human should be around soon to offer more advice. But you can also get helpful information quickly by asking v0.

That error on the domain while the deployment URL works almost always means the alias points somewhere other than your current deployment, not that the build is broken. Three things to check:

1. In Settings → Domains, click Edit on ba4varov-weather.vercel.app. If a Git branch is filled in (even "main" with a typo or an old branch), clear it so it follows Production. A domain tied to a branch with no live deployment gives exactly this 404.
2. Check whether another project in your account (an older "weather" project, for example) also lists this domain. Remove it there.
3. Force a fresh alias from the CLI: vercel alias set <your-working-deployment-url> ba4varov-weather.vercel.app, then run vercel alias ls to confirm it points at the right deployment.

If none of that sticks, removing the domain from the project and adding it back usually clears a stale alias.

Are you sure that's the correct subdomain? I also wasn't able to find any record of that domain in use for any current project.

Make sure you have an existing project with a production deployment. The deployment info includes a link to the production domain, so you can use that to rule out any typo that would cause a "deployment not found" error.