The National Weather Service uses three levels. In its own words (weather.gov winter page):
- Watch, "Be Prepared": conditions are favorable for a significant winter storm. Plan your route and timing.
- Advisory, "Be Aware": winter weather is expected, but not bad enough to meet warning criteria. Expect possible travel difficulties.
- Warning, "Take Action": a significant winter weather event. Travel will become difficult or impossible in some situations.
A Blizzard Warning means frequent gusts of 35 mph or more with falling or blowing snow, often cutting visibility to less than 1/4 mile for three hours or more.
The amount of snow it takes for a warning is not the same everywhere: NWS says it is much higher in the Northern Plains than in the Southeast. So a "Warning" in one place and an "Advisory" in another can mean similar snow.
Our roads page shows the NWS alert text unchanged, with its start and end time.