A Heavy Freezing Spray Warning is issued by the National Weather Service of the United States to warn vessels that rapid accumulation and icing of freezing water droplets due to a combination of cold water, wind, cold air, and vessel or vehicle movement is likely.
Accumulation rates of 2 cm per hour or greater must be possible for a warning to be issued, or else a freezing spray advisory would be issued.
[1] The following is an example of a Heavy Freezing Spray Warning issued by the National Weather Service office in Marquette, Michigan.
[2]