What's the difference between freezing rain, sleet and snow?
(WHTM) — Winter storms can be impactful, but they produce more than snow. They could mean a mixed bag of precipitation.
Freezing rain, sleet, and snow can all cause headaches when driving or cleaning off sidewalks and driveways.
So what is the difference between them?
According to the National Severe Storms Laboratory (NSSL), freezing rain occurs when snowflakes fall into a warmer layer of air and melt into rain.
When the water hits a second layer of freezing air as it falls, it becomes cold again, but not enough to make it freeze. It freezes on contact as long as the surface the droplet hits is below 32 degrees Fahrenheit.
This freezing of water makes a glaze of ice leaving surfaces extremely slick and dangerous to walk or drive on. The water can also freeze around trees, power lines and other surfaces. A significant accumulation of freezing rain lasting several hours is called an ice storm.
Sleet happens when snowflakes only partly melt when they enter a warm layer of air as they fall through the atmosphere to the ground. Think of falling sleet as droplets of slush.
When the slush droplets hit the second layer of freezing air, they freeze as they fall. When they hit the ground, they are considered frozen raindrops that bounce on impact.
Snow is the coldest of winter weather precipitation. This is an accumulation of ice crystals that cling together as they fall to the ground.
Snow continues to fall when the temperature remains at or below 32 degrees Fahrenheit from the base of the cloud to the ground.
There is one more term that you may have heard and have wondered what it means:
Graupel, as defined by the NSSL, are soft small frozen pellets formed when supercooled water droplets freeze onto a snow crystal. If the process, called riming, is particularly intense, affected snow crystals can grow to a noticeable size but not more than 0.2 inches.
Since graupel, sometimes called snow pellets or soft hail, is not fully frozen, pellets usually melt and disintegrate when handled.