A Look at Types of Winter Precipitation & Black Ice

 As a meteorologist, I've heard people get confused over various forms of Winter precipitation. Here's a page from the National Weather Service to explain the types to you: Snow, Sleet, Freezing Rain and Rain (and I added Black Ice, although not a precip type, it's a winter hazard).   IMPORTANT NOTE:  Hail is NOT a wintertime thing, unless you have strong Thunderstorms. Hail is caused by updrafts pushing raindrops high into thunderstorms, causing them to freeze and drop . Here's your Winter Precipitation lesson: 

(Image: Winter precipitation types. Credit: National Weather Service) 

Different types of winter precipitation & Black Ice

It is important to know the difference between snow, sleet and freezing rain.

(Photo below: Snow in Berwick, Maine, January 2023. Credit: MaineNewsNow)

1) Snow forms when the entire layer of air is sub-freezing. Snow consists of ice crystals and is white and fluffy.

2) Sleet forms when the layer of sub-freezing air is fairly deep at 3,000 to 4,000  feet. This allows time for the water droplet to freeze into a tiny piece of ice and become sleet as it falls to the surface. Precipitation in the wintertime that falls as tiny ice pellets is sleet.  

(Photo above, right: Sleet falls as clear ice pellets. Photo by Ranveig via Wikimedia Commons.) 

(Photo above: Freezing rain on a branch. Credit: NOAA Photo Library/Mike Shelby, Maryland)

3) Freezing rain forms when the sub-freezing layer is very shallow. At 2,000 feet from the surface, temperatures are above freezing, so any precipitation that falls is liquid. Once rain hits that shallow, cold air near the surface, it freezes on contact with any object.

(Photo above: Rain on a window in July in Maryland. Credit: R.G.)

4) Rain is water falling in drops condensed from vapor in the atmosphere.  Since we all know what it is, you may not know the origin of the word. The word comes from the Middle English "rein," which comes from Old English word, "regn"  meaning-  "rain, descent of water in drops through the atmosphere," and that was taken from Proto-Germanic *regna." - So the word has morphed over the centuries to the "rain" we know today.

(Photo above: Black ice resulting from melting snow. Credit: https://www.lakewingra.org/) 

5) Black Ice - Although not a form of precipitation, black ice occurs when a surface is wet from melting snow or rain, and freezes when temperatures drop below 32F/0C. Black ice, sometimes called clear ice, is a thin coating of glaze ice on a surface, especially on streets. The ice itself is not black, but visually transparent, allowing the often black road below to be seen through it.