Just to echo the others here, I have lost signal 3 times to my Dish Network system over the past 3 years. Each time, it's followed by me walking outside with a broom to knock the 6 or so inches of snow away from the dish. Keep in mind this has only been snow that could actually stick to the dish, and there are things you can spray on them to help prevent this if you frequently get snow.

Rain has never dropped my signal below usable in the summer time. The big thing Dish warns about winter install though is any trees in the way could block out the signal come spring time with new leaves.

And yes, go the DBS route, it's well worth it to avoid cable companies.