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Weather
Unit 8
Term | Definition |
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Weather | the condition of the atmosphere at a certain time and place |
Climate | the average weather condition in an area over a long period of time determined by two factors—temperature and precipitation |
Humidity | the amount of water vapor in the air |
Condensation | the process by which a gas, such as water vapor, becomes a liquid |
Dew Point | the temperature at which a gas condenses into a liquid; at its dew point, air is saturated |
Cloud | a collection of millions of tiny water droplets or ice crystals |
Cumulus Clouds | white, puffy fair weather clouds |
Stratus Clouds | low level layered clouds that cover the sky |
Cirrus Clouds | high level feathery clouds made of ice crystals |
Precipitation | water, in solid or liquid form, that falls from the air to Earth; there are four major forms of precipitation—rain, snow, sleet, and hail |
Air Mass | large body of air where temperature and moisture content are similar throughout |
Continental Polar (cP) | air mass that is dry and cold (from Canada) |
Maritime Polar (mP) | air mass that is wet and cool (i.e. North Pacific Ocean) |
Continental Tropical (cT) | air mass that is dry and hot (i.e. desert southwest) |
Maritime Tropical (mT) | air mass that is wet and warm (i.e. Gulf of Mexico) |
Front | the area in which two types of air masses meet |
Low Pressure Cyclone | pressure that usually brings wet or stormy weather |
High Pressure Anticyclone | pressure that usually bring dry, clear weather |
Thunderstorm | small, intense weather systems that produce strong winds, heavy rain, lightning, and thunder |
Tornado | a small, spinning column of air that has high wind speeds and low central pressure and that touches the ground |
Hurricane | large, rotating tropical weather system that has wind speeds of at least 120 km/h; form over warm tropical ocean water |
Storm Surge | a wall of water that builds up over the ocean because of the strong winds and low atmospheric pressure from a hurricane |
Weather Forecast | a prediction of weather conditions over the next 3 to 5 days |
Thermometer | a tool used to measure air temperature |
Meteorologist | person who observes and collects data on atmospheric conditions to make weather predictions |
Barometer | an instrument used to measure air pressure |
Anemometer | instrument used to measure wind speed |
Isobars | lines that connect points of equal air pressure |