1. Knowing Your Weather Terms

2. Climate and Weather Climate: The average weather condition in an area over a long period of time at a certain place Weather: The condition of the atmosphere at the present time at a certain place

3. Air Pressure Atmospheric Pressure: The pressure exerted on the surface by the atmosphere. Atmospheric pressure is exerted equally in all directions up, down and sideways. A barometer is used to measure atmospheric pressure in millibars or inches (30 inches is about normal)

4. Solar Radiation/Temperature Solar Radiation: The energy from the Sun used to heat Earth Temperature: The heating of the atmosphere by solar radiation measured by a thermometer

5. Solar Radiation

6. Humidity/Relative Humidity Humidity: The amount of moisture in the atmosphere. Relative Humidity: the percentage of moisture in the atmosphere. At 100% the atmosphere is saturated and precipitation will begin to fall

7. Air Masses High Pressure Air Mass: This air mass has a high barometric pressure. It is usually cool dry stable air which sinks. The air moves from a high pressure system to a low pressure system Low Pressure Air Mass: This air mass has a low barometric pressure. It is usually warm moist and unstable air which rises

9. Low Pressure System Fronts Warm Front: The leading edge of a low pressure system the beginning of unstable weather conditions. Cold Fronts: The trailing edge of low pressure systems. This can bring violent storms depending on the difference of air pressure on either side of the fronts. Stationary Front: When a warm and cold front meet and neither overtakes the other. This front can cause periods of unstable weather

10. Weather Map

12. Jet Stream Jet Stream: Narrow band of high-speed winds that blow in the upper troposphere and lower stratosphere. Polar Jet Stream is found at the boundary between the cold polar air and warm tropical air. These jet streams become the steering mechanism for high and low pressure systems

14. Air Masses that affect North American Weather a. Maritime Polar Pacific b. Continental Polar Canadian c. Maritime Tropical Pacific d. Maritime Tropical Atlantic