It’s not open source but Rain Alarm draws a circle around you on the map and alerts you if weather radar detects any precipitation entering that circle. I don’t know if that’s what you want but it’s what I want in a rain notification and it’s the only app I’m aware of that does it.
I used nothing but Slack for about 15 years. Other distros gave me.problems, hell, I compiled Gentoo from source but was never even successful at installing some of the newbie distros like Ubuntu, but Slack was always simple and rock solid. I wasn’t the best at resolving dependencies, I’d just build and install anything it said I needed. I think I’ve had more than one version of Python or Perl installed at a time, but it never mattered. Every few years I’d wipe everything and reinstall.