I’ll look into adding this if I have some time.
The app now supports watchOS 4 and can potentially have a complication, however in testing the complications have a very small CPU and network budget, so it can only update a few times per hour, then it gets stuck on the last update. This makes it show the wrong prediction for a while. I’m looking into ways around it to reduce the CPU and network, but it is a fundamental issue with the way complications work in watchOS.Glenn commented
I’d also like to see some watch integration. Especially with the new Siri watch face. I think it would be perfect to see the notice on the screen as the rain approaches.