After 15 months of on-and-off work, I'm finally ready to show off Weather Now v5.0, currently in development.
I started building the API and UI projects on top of the core and automation features around Thanksgiving, spending about 45 hours over the past 5 weeks on it. Overall, I've worked about 200 hours to get it to this point, starting with an empty Visual Studio solution file and an empty Microsoft Azure subscription.
Since about 99% of what you can't see already exists, I don't expect it will take me another 15 months to build the stuff you can see. In fact, I only have 21 more JIRA cases (out of 187 so far) to bring it to production. Adding an existing v4 feature to v5 just requires creating the Blazor page, API method, and glue code, which shouldn't take more than 2-3 hours per item, including testing.
Check in frequently. I push updates a few times a week at this point, so you should see pretty rapid changes until I launch the production release (I hope) before the end of March.