Winter Weather Terminology
Winter storms can happen gradually or abruptly during the Michigan winter season. Learn the terms and know what do before, during and after a winter storm emergency or disaster.
Snow Squall Warnings: Snow squalls are unique, extremely localized extreme weather events that can result in high impact to the public and commerce. It may have little to no advance warning (maybe up to 1 hour). It will be targeting conditions that may cause Large Pile-Ups. Will not be issued during Winter Storm Warnings. May/May not be issued during Winter Weather advisories.
Sleet: Rain that turns to ice pellets before reaching the ground. Sleet also causes moisture on roads to freeze and become slippery.
Freezing Rain: Rain that freezes when it hits the ground, creating a coating of ice on roads, walkways, trees, and power lines. Small accumulations of ice can be a significant hazard. An inch or more of ice can paralyze a region for days to a week or more. Heavy accumulations of ice can bring down trees and topple utility poles and communication towers.
Winter Weather Advisory: This product is issued by the National Weather Service when a low pressure system produces a combination of winter weather (snow, freezing rain, sleet, etc.) that present a hazard, but does not meet warning criteria. Weather conditions are expected to cause significant inconveniences and may be hazardous. Caution should be used if traveling. This generally indicates in the Lower Peninsula: 4 to 5 inches are expected in a 12-hour period. In the Upper Peninsula: 4 to 7 inches of snow are anticipated in that same time period.
Winter Storm Watch: This product is issued by the National Weather Service when there is a potential for heavy snow or significant ice accumulations, usually at least 24 to 36 hours in advance. Conditions are favorable for severe winter weather, with the possibility of heavy sleet, heavy snow, ice storm, heavy snow and blowing snow—or a combination of events.
Winter Storm Warning: Severe winter conditions are imminent. This product is issued by the National Weather Service when a winter storm is producing or is forecast to produce heavy snow or significant ice accumulations. A winter storm warning for heavy snow generally indicates snowfalls of at least 8 inches.
Blizzard Warning: Issued for winter storms with sustained or frequent winds of 35 mph or higher with considerable falling and/or blowing snow that frequently reduces visibility to 1/4 of a mile or less. These conditions are expected to prevail for a minimum of 3 hours.
Wind Chill: Wind chill is the temperature it “feels like” when you are outside. The National Weather Service provides a chart to show the difference between air temperature and the perceived temperature and the amount of time until frostbite occurs. For more information, visit: http://www.nws.noaa.gov/om/cold/wind_chill.shtml.
Frost/Freeze Warning: Issued during the growing season when surface temperatures are expected to drop below freezing over a large area for an extended period of time.