Snow Drift from a Sawtooth Roof

[Aldoman]

I have a snow drift question.

I'm working with a sawtooth roof and the customer wants to add a canopy, at a lower elevation, at the end of the roof. The sawtooth ridge runs parallel to the edge of the roof where the canopy is to be added.

So how would one calculate the snow drift on the canopy? One can argue that the ridge of the sawtooth acts like a parapet and precludes the snow from drifting beyond it onto the canopy. But I'm not sure if I would underestimate the drift that way. ASCE7 doesn't appear to address this.

Thanks