© 2008 Michael Doig
•The term weather describes the state of the air at a particular place and time.
•Weather can change from minute-to-minute, hour-to-hour, day-to-day, and season-to-season.
Weather
Climate
© 2008 Michael Doig
•The normal pattern of weather experienced in a particular area over a long period of time is known as the climate.
•For example, tropical countries have hot climates and the Antarctic has a cold climate.
© 2008 Michael Doig
•Temperature, pressure, air movement, and moisture are the four critical factors that determine weather.
4 Weather Factors
© 2008 Michael Doig
•Latitude, proximity to water, proximity to mountains and elevation are four critical factors that determine climate.
4 Climate Factors
Daily Weather Variables
© 2008 Michael Doig
•Date & Time - Calendar & Chronograph
•Temperature - Celsius Thermometer
•Air Pressure - Barometer
•Relative Humidity - Psychrometer
•Dew Point - Dew Point Apparatus
•Rain - Rain Gauge
•Wind Speed - Estimate
•Wind Direction - Weather Vane
•Visibility - Estimate
© 2008 Michael Doig
•Page 31
•0 mph - Smoke rises
•1-3 mph - Smoke drifts
•4-7 mph - Flags stir
•8-12 mph - Leaves move
•13-18 mph - Tree branches move
•18-24 mph - Trees sway
•25-31 mph - Flags beat
•32-38 mph - Flags extend
Estimating Wind Speed
Station Models
© 2008 Michael Doig
•A station model is a symbolic illustration showing the weather occurring at a given reporting station.
•Meteorologists created the station model to plot a number of weather elements in a small space on weather maps.