Mr Panbo does a side by side comparo of both XM and Sirius's ability to track weather in real time. He's using them in a marine capacity, but there's no reason why that info couldn't be used to help landlubbers on their morning commutes sometime soon. The Verdict: Sirius didn't see some storms, but accurately predicted drizzle. XM saw dark clouds and wind direction/speed, but wasn't any more reliable than your average weather man.
Live Satellite Weather Monitoring [ Panbo's Marine Electronics and Communication Weblog ]