I would ignore that model and go off typical D3-5 lead in that "look" ;O I feel like it'll be a dousing for some but 1-2"++?, while most are .25-.50
BUT I have no idea what is going on, perhaps a pro can chime in.
I don't know about that- not 100% anyway - seems like at least some decent showers will roll through. I'd wager at least .50 for your locale, but is real