How is the subsoil moisture determined on the Netro App for each zone?

Smart watering disables my program as it thinks its going to rain, how do I override it - if the weather forecast doesnt pan out or we dont get enuf rain

Not really a question but a shout-out about the changes to the app.  l found the wonderful new additions that the Netro team just made.  I suggest everyone check out the new additions.  I have tweked a couple of my zones and Very pleased.  Suggest everyone check it out!