There are six main components of weather, humidity, cloudiness, precipitation, temperature, atmospheric pressure and wind.

Weather and Atmospheric Moisture

Humidity

Humidity is the amount of water vapour in the air. We usually use the term to mean relative humidity, the percentage of water vapour a certain volume of air is holding relative to the maximum amount it can contain. If the humidity today is 80%, it means that the air contains 80% of the total amount of water it can hold at that temperature. What will happen if the humidity increases to more than 100%? The excess water condenses and forms precipitation. This is a simplistic look at this topic because depending on the temperature of the air, the capacity of water content per kilogram of air changes. Warm air can hold more water vapour than cool air, so raising or lowering the temperature can change the air’s relative humidity. The temperature at which air saturated air can condense is called the dew point. This term makes sense because the water condenses from the air like the morning dew. Another example of this would be a glass full of ice water. Depending on the temperature and humidity levels for the day, if the contents in the glass are cooler than the surrounding air, the glass will cause the moisture in the air around it to condense along the surface.

Clouds

Clouds have a big influence on weather by preventing solar radiation from reaching the ground; absorbing warmth that is re-emitted from the ground; and as the source of precipitation. When
there are no clouds, there is less insulation. As a result, cloudless days can be extremely hot, and cloudless nights can be very cold. For this reason, cloudy days tend to have a lower range of
temperatures than clear days. There are a variety of conditions needed for clouds to form. First, clouds form when air reaches its dew point. This can happen in two ways:

1. Air temperature stays the same but humidity increases. This is common in locations that are warm and humid.
2. Humidity can remain the same, but temperature decreases. When the air cools enough to reach 100% humidity, water droplets form. The air cools when it comes into contact with a cold surface or when it rises.

Rising air creates clouds when it has been warmed at or near the ground level and then is pushed up over a mountain or mountain range or is thrust over a mass of cold, dense air. Water
vapour is not visible unless it condenses to become a cloud. Water vapour condenses around a nucleus, such as dust, smoke, or a salt crystal. This forms a tiny liquid droplet. Billions of these
water droplets together make a cloud.

Clouds are classified in several ways. The most common classification used today divides clouds into three separate cloud groups which are determined by their altitude and if precipitation is
occurring or not.

• High-level clouds form from ice crystals where the air is extremely cold and can hold little water vapour. Cirrus, cirrostratus, and cirrocumulus are all names of high clouds. Cirrocumulus clouds are small, white puffs that ripple across the sky, often in rows. Cirrus clouds may indicate that a storm is coming.
•  Middle-level clouds, including altocumulus and altostratus clouds, may be made of water droplets, ice crystals or both, depending on the air temperatures. Thick and broad altostratus clouds are gray or blue-gray. They often cover the entire sky and usually mean a large storm, bearing a lot of precipitation, is coming.
•  Low-level clouds are nearly all water droplets. Stratus, stratocumulus, and nimbostratus clouds are common low clouds. Nimbostratus clouds are thick and dark that produce precipitation. Clouds with the prefix ‘cumulo-‘grow vertically instead of horizontally and have their bases at low altitudes and their tops at high or middle altitudes. Clouds grow vertically when strong
  unstable air currents are rising upward.

Precipitation

Precipitation is an extremely important part of the weather. Some precipitation forms in place. The most common precipitation comes from clouds. Rain or snow droplets grow as they ride air
currents in a cloud and collect other droplets. They fall when they become heavy enough to escape from the rising air currents that hold them up in the cloud. Millions of cloud droplets will
combine to make only one raindrop. If temperatures are cold, the droplet will hit the ground as a snowflake. In meteorology, the various types of precipitation often include the character or phase of the precipitation which is falling to ground level. There are three distinct ways that precipitation can occur. Convective precipitation is generally more intense, and of shorter duration, than
stratiform precipitation (arranged in layers). Orographic precipitation occurs when moist air is forced upwards over rising terrain, such as a mountain. Precipitation can fall in either liquid or solid phases, or transition between them at the freezing level. Liquid forms of precipitation include rain and drizzle and dew. Rain or drizzle which freezes on contact within a subfreezing air mass gains the preceding adjective “freezing”, becoming known as freezing rain or freezing drizzle. Frozen forms of precipitation include snow, ice crystals, ice pellets (sleet), hail, and graupel. Their respective intensities are classified either by the rate of fall or by visibility restriction.