Episode 109: Weather Part I

Rain Dynamics

Rain and precipitation are influenced by various atmospheric conditions, including temperature and air turbulence. James Fodor explains that as water falls from higher altitudes, the increasing temperature can cause it to evaporate before reaching the ground. Turbulent air promotes precipitation by causing water droplets to collide and form larger droplets, which can then fall as rain or other forms of precipitation 1.

Raindrops vary in size from a fraction of a millimeter to about 9 mm in diameter.

--- James Fodor

The shape of raindrops is not the classic teardrop but more spherical or oblate, depending on their size. The form of precipitation, whether rain, snow, or ice, largely depends on the air temperature from the clouds to the ground 1.

   

Precipitation Processes

The process of precipitation involves complex interactions between temperature layers in the atmosphere. James Fodor describes how precipitation can start as snow in cold cloud layers and then melt into rain as it passes through warmer layers. If it encounters a colder layer again, it can refreeze into ice pellets or hail 2.

It's actually quite complicated as to exactly what form water takes in different combinations of temperature and humidity.

--- James Fodor

This intricate process can result in various forms of precipitation, such as freezing rain, depending on the specific temperature and humidity conditions encountered during its descent 2.

   

Fog and Precipitation

Fog is a type of cloud that forms close to the ground and is considered a form of precipitation. James Fodor explains that fog can form due to radiation cooling or advection, where moist air passes over a cooler surface, leading to condensation 3.

Precipitation is any product of condensation of atmospheric water vapor that falls under gravity.

--- James Fodor

This process results in various forms of precipitation, including rain, snow, sleet, and hail, depending on the atmospheric conditions. Understanding these processes helps in comprehending the diverse manifestations of precipitation 3.