Earth’s Weather Weather – state of the earth’s atmosphere at a certain time and place Climate – the year-round weather typical of a certain place

Understanding Weather A. Factors Causing Weather 1. Sun’s energy 2. Water vapor B. Changing States 1. Increasing energy Evaporation – the rate of evaporation is directly related to temperature

C. Returning to a liquid a. condensation b. dew c. frost

Clouds and Fog 1. Cloud – water vapor in the air condenses into tiny droplets of water 2. Types of clouds a. Cumulus – “to pile” or “to heap” b. Stratus – “layer” c. Cirrus – “wisp” or “curl”

Water vapor condensed in a layer of air near the ground FOG Water vapor condensed in a layer of air near the ground

Air Masses a. Temperature b. Humidity c. Pressure Factors affecting air mass a. Temperature b. Humidity c. Pressure

Fronts and Weather 1. Fronts Two air masses fighting for supremacy 2. Cold front Cold air moves into area covered by mass of warmer air 3. Warm front Lighter warm air meets a cold air mass