My 2 cents would be to look up the best meteorologist in your area, not just a TV personality, but someone with actual creds as a meteorologist. There's usually one in every major city market.
A meteorologist will have access to multiple models and if they're worth anything, they'll be looking at all of those models to come up with a forecast. Your phone app, 9 times out of 10, uses one model with no interpretation. I don't trust them more than a day or two out. I really don't 100% trust any forecast that's a week out. You might have an indication of what might happen, but no one worth their salt is going to give specific snow totals that far out. It's just too complicated of a science to do that with any accuracy this far out.
I'm not saying don't keep an eye out or prepare for the worst. I'd just make sure you're using accurate data before you jump to a plan that's going to cost you money, time, etc.