Heavy snow is used to describe conditions when snowfalls will add up to 6 more inches in a 12 hour period or 8 inches or more in a 24 hour period.
Snow is dangerous to travelers since it causes the road to become slippery.
One of the more dangerous times during Winter storms is when the road initially becomes snow covered. A thin layer of snow offers less traction than an inch or more. When traveling during a falling snow, remember to be especially careful when the road is first covered with snow. Snow often leads to other problems which will be described below. Thundersnow is caused by vigorous clouds within the storm.