- You can add more water vapor to the air. Aim: How do clouds form? Do Now: In your notebooks, answer these questions in order to understand how clouds are made. - Explain how you can make the air have a relative humidity of 100% - You can add more water vapor to the air. - You can lower the temperature which make the air smaller and more filled.

I. Formation of Clouds Forms when warm air rises. Rising air cools due to expansion. (upper atm. has lower pressure) c) Air temp. equals the dew point temperature (RH = 100%).

RISING AIR which LOWERS the TEMPERATURE d) Water vapor condenses around small solid particles called condensation nuclei. Which is the most important step in creating a cloud? RISING AIR which LOWERS the TEMPERATURE

II. What makes air rise? a) Warm air rises because it is less dense. b) Orographic lifting: Mountains force the air to ascend. (rise) rising air expands and cools, which lowers the temperature. **When air temperature = dew point temperature (RH = 100%)condensation occurs**

Orographic Lifting Diagram

III. Cloud Types: Cirrus: light and feathery. - Composed of ice crystals. 2. Cumulus: “puffy cotton balls” 3. Stratus: smooth layered clouds - “pancake clouds”

IV. Fog Is a cloud in contact with the ground. relative humidity reaches 100% at ground-level.

V. Precipitation - occurs when cloud droplets grow heavy and fall to the Earth. If the temperature is below 320F, snow may occur.

Closure: Use the words in the box to create 2 different sentences that describes how clouds form. You do not need to use all the words. You can use additional words. RISE CLOUD RELATIVE HUMIDITY 100% MOUNTAINS EXPAND COOLS CONDENSTATION DEWPOINT TEMPERATURE PRECIPITATION WARM CONDENSATION NUCLEI