diad,
I have been using the Sirius weather for about 6 months on the TZT2 and I am still getting to know everything.
To get the Sirius radar to display Swipe up from the bottom edge, to display the layer menu (or you can also use the right slide out menu and tap layer).
On the layer menu the first item on the left should have an option to select Sirius Radar or NOWRAD radar to display. Once that is turned on it takes some time for the rain to show up on the chart, I think it gets an update every 5 minutes or so.
The next step is to tap on the chart and slide the menu up until you see Adv WX and WX. Within those you can turn on or off different items to display, Lightning, wind, SST ect.
The one I like the most is the Storm Track. It is a simple arrow that shows the direction a storm is headed, it takes a lot of guess work out of watching a radar loop animation.
I am still trying to figure out the best way to setup the Sirius weather NOWRAD on an animation loop. Currently it seems like it loops realtime weather and forecast all together in one animation.
Hope this helps, I am trying to explain it while away from the boat.
Diggin'Deep