Sleet
Topic: Water in the Atmosphere: Humidity, Condensation, Clouds and Precipitation · NCERT: Class 11, Ch 10 "Water in the Atmosphere"
Meaning
Sleet is a form of precipitation made of small ice pellets. It forms when a warm layer of air sits above a freezing layer near the ground. Snow or ice melts into raindrops in the warm layer. The raindrops then freeze again as they fall through the cold layer below. The pellets are no bigger than the raindrops they came from. Sleet is patchy in both time and place, and it makes roads and runways slippery.
Example
Sleet is common in winter in the north-eastern United States and eastern Canada. Warm air often rides over a thin layer of freezing air near the ground there.
Don't confuse with
- Hail: Hailstones are bigger, rounded lumps of ice with layers like an onion. They form when drops are carried up again and again inside a cumulonimbus (a tall thunderstorm cloud). Sleet pellets freeze only once, as they fall.
- British "sleet": In Britain the word means rain and snow falling together, not frozen pellets.