Introduction

When water vapor in the atmosphere condenses and falls to the ground under gravitational force in a liquid and solid state, it is called precipitation. Precipitation does not mean rainfall. Rainfall is a form of precipitation. There are some other forms of precipitation like rainfall. Freezing rain and snow are two such forms. These two forms are solid forms of precipitation. Here we discussed the difference between freezing rain vs snow.

The precipitation of atmospheric moisture occurs in different ways. Such as the temperature of the dew point where the air is saturated and condensation, the cloud’s altitude and types, the process of adiabatic cooling, and the atmospheric condition through which the cloud droplets pass in terms of temperature.

If condensation occurs at a temperature above the freezing point, the precipitation takes place in a liquid state. But when the condensation occurs below the freezing point, the precipitation occurs in solid conditions such as freezing rain, snowfall, etc. Although snow and freezing rain are in the form of precipitation, they are slightly different from each other (1) & (2).

What is freezing rain?

When very light rains occur below 0°C temperature on the ground surface, they are frozen before falling to the earth’s surface, and hence these types of precipitation are called freezing rain. Sometimes they are known as crachins. Such type of precipitation generally causes the deposition of thin ice over leaves, twigs of plants, wires, telephone poles, etc.

Freezing rain usually occurs from the Nimbostratus. It is one of the riskiest rainfall in the winter season. Freezing rains can damage the environment. When the raindrops hit the trees, it freezes on their branches. It can snap and break branches, causing damage to the plant (1).

Features

• It is made of liquid droplets.
• In this case, the droplets become supersaturated when they pass through a sub-freezing zone.
• Freezing rain falls like rain, but when it touches the ground, it freezes.
• They are ice crystals like stars.
• It forms when the sub-freezing layer is very shallow, with cold temperatures at the ground.
• Freezing rains are usually the weather threat that causes the most car accidents in the winter season.
• It occurs in areas where snowfalls occur in winter.
• This type of precipitation develops through supersaturated warm-rain processes (2) & (3).

Formation process

Freezing rain occurs mainly in the winter season. In winter, when the freezing point at the cloud level is below 0°C, any droplets falling from the clouds are supercooled. That means they are exposed to a cold layer of the air mass or a surface where the temperature is below 0°C. And then the droplets freeze immediately before falling to the ground in the form of precipitation. Thus freezing rain is formed.

When snow falls, it enters a layer of warm air. Here snow and ice particles break into raindrops. Then raindrops start falling towards the surface. There is a layer of the cold air mass. The raindrops enter this layer and cool to temperatures below 0°C.

This layer is so shallow. These raindrops freeze before they fall to the ground as they pass through the cooling air mass. They fall on the ground and adjacent surfaces of the earth like plant branches, the roofs of houses, electricity poles, the roads, etc., and create thin layers (2).

What is snow?

Snow is a solid form of precipitation that exists in the form of crystals in the Earth’s atmosphere and falls to the ground. It is a form of ice. It is formed when condensation occurs below the freezing point (less than 0°C). The fall of snowflakes is called snowfall. Snowflakes are formed when the air temperature is greater than -5°C but less than 0°C.

These forms of precipitation occur when water in the atmosphere becomes frozen. There are different sizes and shapes of snow. It is converted into water vapor by the sublimation process. On the other hand, deposition is the process by which water vapor is converted into snow. The water released from the clouds freezes at low temperatures in the upper layers of the atmosphere turns to ice and falls to the ground in the form of snow (1).

Features

• Snow is the precipitation of white and opaque grains of ice.
• It exists in crystalline form.
• This form of precipitation is actually a solid form of water or ice.
• In winter, when the temperature drops below freezing point, snow falls from the clouds.
• When snow falls into the ground it looks beautiful.
• It also has a bad impact on humans and the environment.
• When dew points of air are below freezing point then snowfall on the earth’s surface.
• It consists of ice crystals. The average density of ice crystals is 0.1g/cc.
• Snow is observed in colder climates and higher altitudes.
• Sometimes it melts when it reaches the surface or ground.
• This type of precipitation usually occurs from the cirrus clouds.
• When the surface temperature is below freezing, it will reach the ground (1).

Formation process

Snow is formed in clouds when temperatures are below the freezing point. Then water vapor directly condenses into ice particles. Mainly it originates when atmospheric temperatures are low, the air is dry.

In the high mountain areas, cirrus clouds in the upper sky have very cold water particles. However, these water particles do not participate directly in precipitation. Water vapor condenses around ice particles in cold clouds and turns into ice.

As a result, the latent heat that is emitted often evaporates the water droplets. This makes the air drier. Then the liquid water particles disappear and the ice gets larger. These are heavy so they cannot float in the air. And falls as snowfall due to the force of gravity on the surface. In this way, snowfall is formed (1).

Differentiate between freezing rain vs snow

Freezing rain and snow are two important solid forms of precipitation. The formation process of snow and freezing rain is the same. However, there are some differences between these two forms of precipitation. Below is a discussion of freezing rain vs snow.

Q&A

1. What is freezing rain?

Freezing rain is a form of precipitation. Warm oceanic air rises above the cold air and turns into cool water particles. When this cool water particles downhill they come through a shallow layer. As a result, these cold-water particles freeze and fall to the ground in the form of precipitation. This is known as freezing rain (2).

2. How is freezing rain formed?

In winter, when the freezing point at the cloud level is below 0°C, any droplets falling from the clouds are supersaturated. That means they are exposed to a cold layer of the air mass or a surface where the temperature is below 0°C. And then the droplets freeze immediately before falling to the ground in the form of precipitation. Thus freezing rain is formed (1).

3. What is the difference between freezing rain and sleet?

Besides there is a difference between freezing rain vs snow, freezing rain and sleet are also different and are two important forms of precipitation. Their formation process is also the same. But there are some differences between them. Such as-

• Freezing rain occurs when the frozen air layer is so thin that there is not enough time for the water particles to freeze before they reach the ground.

On the other hand, when rain and snowfall together, it is called sleet. It is formed when the freezing air along the surface is thicker. As a result, some water particles freeze before they reach the earth’s surface, and some water particles fall in the form of rain.

• A shallow cooling layer is required for the freezing rain. There is no deep cold layer required for sleet formation.
• Freezing rains are ice crystals like stars. But in this case, sleet, rain, and snow together fall to the earth’s surface.
• When freezing rain touches the ground, it freezes. On the other hand, sleet freezes before it hits the ground.

4. How to drive in freezing rain?

Freezing rain is very dangerous for driving. When it falls into the ground, it forms a thin icy layer on the road. As a result, the road is very slippery. So here are the things to keep in mind when driving on these slippery roads:

• Drive slowly because freezing rain creates a thin and slippery layer of ice on the road which can be especially dangerous when braking. As a result, the car skidded.
• Stay home, only go out if necessary.
• Leaves extra space between two cars.
• Avoid unnecessary road changes.
• A type of tire that is used on car wheels to drive on snowy roads. These tires are used.
• Some important winter safety kits need to be used such as a snow brush, gloves, a hat, hand warmers, etc.

5. What is the difference between sleet and freezing rain?

Written By: Manisha Bharati