Types of precipitation
Snow, like sleet and hail, is only solid precipitation. It forms when temperatures are low, and there is moisture in the form of tiny ice crystals in the atmosphere. Note that temperatures do not have to be below zero or 32°C or 32°F for the snow to form.
The air consists of tiny dust and ice particles, and both are very key to snow formation. When the moisture in the air makes contact with the particles in low-temperature conditions, they form tiny ice crystals. Snowflakes start small in size, but with time more water vapor may condense onto the ice crystals, or other tiny ice crystals may stick together to form larger snowflakes.
As they grow in size, the snowflakes become heavy, and gravity takes over. Snow will stay in its snow-form as long as atmospheric temperatures remain evenly low. If temperatures rise before the snowflakes reach the ground surface, they will melt into water (rain).
Snowfall can be defined as slight, moderate, or heavy. When snow is accompanied by strong winds it can create blizzards and drifts.
After condensation, water droplets fall to the ground in the form of rain. Unlike snow, above freezing temperatures from the cloud level down to the earth’s surface keeps the rainwater from turning into ice. Precipitation, therefore, reaches the ground as rainwater.
Sleet is simply frozen raindrops falling from the sky. Sleet begins to fall as rain (liquid), but encounters freezing conditions, causing the rain-drops to freeze before hitting the earth’s surface. Sleet may have a similar size as a raindrop. They don’t last for long when they fall onto the ground.
Hail develops from powerful thunderstorms.Freezing temperatures in the clouds cause raindrops to freeze. As they fall, powerful updrafts send the stones back into the clouds again. As they circle around in the clouds, they grow in size from the additionalmoisture they pick along. Hailstones can be very destructive if they fall on your car or building. Imagine an ice ball the size of a tennis ball coming down on your roof. They can be as small as peas and as large as a softball. The more powerful the thunderstorms, the longer the hailstones will stay in the clouds, growing in size.
It happens when rain fromabove-freezing temperatures fall, butjust before they get to the ground are chilled by freezing conditions. The layerof freezing is thin and cannot freeze the raindrops. However, the water freezesimmediately upon touching the ground. Freezing rain is probably the most dangerous. They cause black-ice on our roads and pathways. They also result in the layers of ice on power lines and ice stalactites that form from the roof of houses.