XM WX does work on land, and in the air - at $99/mo! XM WX is intended to give serious detail - the kind of detail storm chasers need. For normal usage in a vehicle (especially a motorcycle) XM WX is too much.
XM NavWeather is different in that it is designed for drivers (riders) with the appropriate information to see/avoid weather. The new Acura's have this feature, as does the Bushnell Onyx. The problem is that an Acura has four wheels and a Busnell is intended for hikers and hunters.
XM NavTraffic is useful for some in urban areas (we don't do traffic in New England (mostly)). NavTraffic does have "basic" (read sucky) weather info.
personally want - and what NavWeather has - is a visualization of a thunderhead in realtime. I want to see rain patterns in big red blotches so I can say of f#%$ and maneuver around it. This is the technology and the promise.
I will bet that the only reason Garmin does not do this for the Zumo seres is political. They do it for other garmin devices. They make the hardware for the service.
I wrote both Garmin and XM about this topic. I got the typical PR
statement. I also called Bushnell to see if they have a vehicle version of the Onyx. This functionality had not occurred to them. DUH!
I am giving thought to having two GPSs on my bike; one for navigation and one just for weather. But why should I do this? Why can't companies like Garmin just actually listen?
This is what happens when a geek goes on a rant.