 The condition of Earth’s atmosphere at a particular time and place.

 The characteristic weather conditions in an area over a long period of time.

 We study weather so that we can predict the future. Fun Fact: Ben Franklin made the first recorded weather forecasts in Poor Richard’s Almanac.

 Making Observations & Collecting Data ◦ Air Pressure ◦ Temperature ◦ Humidity ◦ Wind Speed & Direction ◦ Precipitation ◦ Cloud Cover

 What is it? ◦ The force exerted on you by the weight of the air.  How do we measure it? ◦ Barometer  What unit is it measured in? ◦ US: in (inches of mercury) ◦ Metric: mb (millibars)

 What is it? ◦ The measure of how hot or cold the air is.  How do we measure it? ◦ Thermometer  What unit is it measured in? ◦ US: o F (Fahrenheit) ◦ Metric: o C (Celcius)

 What is it? ◦ The amount of moisture in the air.  How do we measure it? ◦ hygrometer  Scale used to measure it: ◦ 0% - 100%

 What is it? ◦ The measure of how fast the air (wind) is traveling.  How do we measure it? ◦ anemometer  What unit is it measured in? ◦ US: mph (miles per hour) ◦ Metric: km/h ◦ (kilometers per hour)

 What is it? ◦ The direction the wind is blowing.  How do we measure it? ◦ Wind vane  What unit is it measured in? ◦ North, South, East, West

 What is it? ◦ The amount of precipitation that falls.  How do we measure it? ◦ Rain gauge  What unit is it measured in? ◦ US: in (inches) ◦ Metric: cm (centimeters)

 Satellites: Shows cloud cover, warm & cool regions and water vapor.

 Radar: Locate clouds and measure their heights. ◦ Doppler: Special radar that can detect air motion & precipitation.

 Weather Balloons: Collects data about air at different altitudes (heights).

 Ocean Buoys: Measure conditions in the ocean that affect the atmosphere.

 Ground Stations: Contain a number of different instruments to collect data in a particular area.

 Weather Maps  Diagrams  News Reports  Weather Alerts

 The SUN and air.  The sun heats the air around the Earth at different rates, causing wind.