Please don't restrict the alarms to specific locations. It would be nice to add a route you plan to use and specify how fast you're probably travelling and when you start, to get alarms.
Also please make it possible to invert alarms:
I want to set acceptable conditions and beeing alerted if the weather will exceed them.
Also dynamic locations would be nice, that you just specify the radius around your GPS location and the acceptable conditions to get serve weather warnings, and anything which exceeds the acceptable conditions.
I've also seen a feature which notifies you daily about the hours you're able to do certain sports, like hiking or mountain biking. This would be a nice addition.
For the rules I would prefer a interface similar to the current state, which creates rules, which can be extended or modified in an advance view of the rules.
I think Yaml is the optimal language for those kinds of rules, like HomeAssistant is using it.
Hope this input helps 😙🎶