Most types that I have flown give approval for flight in falling or blowing snow but I'm a bit concerned when you ask about ice accretion. Most multi-engine helo's have, in their limitations section, a statement like "Flight in known icing conditions is prohibited."
If you stick to the Flight Manual clearance it is possible to fly in snow but not when icing conditions may also be present.
Although the aircraft may cope, will you? Be aware of things like white-out in re-circulation near the ground when landing or taking off; navigating difficulties in snow covered ground; instrument flying skills (or lack of) in reduced visibility etc. etc.
Your query may be a technical one but, if you are thinking of flying, approach with great caution.