In any one location, it usually occurs briefly as a transition phase from rain to snow or vice-versa, but hits the surface before fully transforming.
[4] Wintry showers is a somewhat informal meteorological term, used primarily in the United Kingdom, to refer to various mixtures of rain, graupel and snow at once.
In the United States, wintry mix generally refers to a mixture of freezing rain, ice pellets, and snow.
During winter, a wide area can be affected by the multiple mixed precipitation types typical of a wintry mix during a single winter storm, as counterclockwise winds around a storm system bring warm air northwards ahead of the system, and then bring cold air back southwards behind it.
Most often, it is the region ahead of the approaching storm system which sees the wintry mix, as warm air moves northward and above retreating cold air in a warm front, causing snow to change into ice pellets, freezing rain and finally rain.