The occurrence of snow in the Seattle Tacoma area is extremely variable and usually melts before accumulating to measurable depths. There are winters on record with only a trace of snow but at the other extreme, over 21 inches has fallen in a 24 hour period.
The rabbit's sense of smell is far more developed than that of the human. Moveable folds inside the rabbit's nose assist in the detection of scent. The sense of smell in a rabbit is present at birth, allowing a newborn to find his mother's teat. Rabbits shift their noses up and down when trying to identify a scent; this is called nose blinking..
They should be warm and round-bellied. The best way to know for sure is to weigh them on a small postage scale or kitchen scale. Write down a description and the weight. If they're gaining weight (1/4 oz. or so), they're being fed. You can handle the babies even if the mother doesn't know you. Domestic rabbits are not that concerned over human smells. Rabbits are not prone to cannibalism, as many people think.