| A | B | 
|---|
| weather | the condition of the Earth's atmosphere at a given time in a given place | 
| meteorology | the scientific study of the Earth's weather | 
| meteorologist | a person who studies the Earth's weather | 
| weather instruments | used to measure weather conditions | 
| convection | circulation in a fluid that results from energy transfer; during this process, warm masses of air rise and cool masses of air sink | 
| water vapor | water that is always in the air | 
| clouds | form when air cool and water vapor condenses on dust or other nuclei | 
| thermometer | weather instument that measures temperature in degrees C or F | 
| barometer | weather instument that measures air pressure in millibars | 
| hygrometer | weather instument that measures humidity in pecentage | 
| wind vane | weather instument that measures wind direction measured in compass points | 
| anemometer | weather instument that measures wind speed in k/hr | 
| forecast | a prediction about what kind of weather to expect | 
| severe weather | weather that is dangerous or causes damage | 
| atmosphere | the gases around the Earth | 
| weather factors | properties of air that affect weather | 
| compressed | forced into a smaller space | 
| pressure | the force of the air pushing in all directions | 
| mass | amount of matter in an object | 
| weight | is the force an object exerts because of gravity | 
| Troposphere | the part of Earth's atmoshpere where weather takes place | 
| different kinds of weather | associated with different seasons |