Snow Squalls are bands of snow that move quickly through a region. A squall will have bursts of snow and wind. They typically do not last very long, but can put down quick accumulations of snow and lead to whiteout conditions with zero visibility.
Here is what a snow squall looks like on Radar:
Driving through a snow squall can be dangerous. If you end up caught in one it is best to reduce your speed and use your low beams instead of high beams to be able to see. It is best to check a weather forecasts and avoid driving through one.
This is how low visibility can be:
The National Weather Service can issue Snow Squall Warnings. This means that a snow squall is occurring or going to occur soon. These are issued within a half an hour to an hour of the squall moving through.