In years past, we've had some problems with quick hoops in the snow.
Eliot Coleman recommends covering the hoops with clear plastic if you
live in a snowy climate, and he's not wrong. Row-cover fabric can tear
under heavy snow loads. And since the snow sticks rather than sliding
off, the PVC hoops can bend and break as well.
If your snow doesn't come
down in bucketloads all at once, though, it's pretty easy to just brush
off the top of the fabric every three to five inches. Don't use a
broom, though --- I tried that last year and it tore through the
row-cover fabric. Gloves are soft enough to be safe as long as you're
gentle.
9.4 inches of snow in the last week and no broken fabric or hoops yet. Success!