In reply to Katzina.W:
There's a common rule-of-thumb for the alcoholic generation; speed in mph divided by ten is equivalent to number of pints of beer drunk.... so at 40mph you'll have a few arm-waving big steps, at 80mph you'll be hanging onto the ground trying to stay attached. Your own mileage may vary...
If the direction of the wind is directly up the gulley, it could be a bit of a chilly funelling experience. If it's directly down the gulley, it doesn't make much difference, just turbulent flow over the top as with all other directions. Valleys are sheltered, local terrain effects can give you higher local speeds and buffeting, but probably nothing too stern at 40mph.
If there's loose dry snow (recent snow, cold temps) you could get a bit of a sandblasting/spindrift experience.
Read the other comments on safety - snow redistributed by wind is where plenty of avalanche hazards originate.
Y