1. WEATHER: TOPIC 7

2. What is an air mass? An air mass is a large body of air in the troposphere with similar characteristics of pressure, moisture and temperature

3. How are air masses characterized? Air masses are characterized by the regions in which they form over. –cA- Continental Artic –cP- Continental polar –cT- Continental Tropic –mP- Maritime Polar –mT- Maritime tropical

4. What are the characteristics of a low pressure? The characteristics of a low pressure, also called cyclones are: -Lowest pressure at the center -Winds blow toward the center -Winds circulate counterclockwise -Usually associated with stormy weather & heavy cloud cover

5. What are the characteristics of a high pressure? The characteristics of a low pressure, also called cyclones are: –Highest pressure at the center –Winds blow away from the center –Winds circulate clockwise –Usually associated with calm and clear weather

6. What is a front? A front is a boundary or interface between two different air masses.

7. What are the different types of fronts? Different types of clouds are: –Cold front- boundary between advancing cold air mass and a warm air mass. The cold air pushes the warm air up like a wedge. –A warm front- boundary between advancing warm air mass and a cold air mass. The warm air mass is forced to rise as it advances –An occluded front- boundary between a cold air mass, warm air mass and a another cold air mass is sandwiches between two air mass. (A sandwich) –A stationary front- when 2 different air masses remain in the same position

8. What is a storm? What are the different types of storms? A storm is a violent or severe disturbance of the atmosphere that usually creates dangerous and destructive conditions Different types of storms include mid-latitude cyclones, hurricanes, thunderstorms and blizzards.

9. What is a mid-latitude cyclone or cyclonic storm? A mid-latitude cyclone is a result from a low pressure system. These storms bring precipitation to the mid latitudes.

10. What is a hurricane and what are its characteristics? A hurricane is a low pressure system in the tropics in which winds blow at 74 mph or more They have rotating bands of precipitation, with a cloudless “eye” at the center. They are rated on a Safir-Simpson scale (which measure how much damage the storm causes).

11. What is a tornado? A tornado is a rapidly rotating extremely low pressure funnel that hangs down from thunderstorm clouds Most tornadoes only last a few minutes. 318 mph is the fastest recorded surface winds. Most damage is actually caused by flying objects Tornadoes are measured on a Enhanced Fajita Scale (EF1, EF2, EF3, EF4….)

12. What is a blizzard? A blizzard is a storm with winds 35 mph or greater associated with considerable amounts of snow.

13. What is a thunderstorm and what are the characteristics? A thunderstorm is a heavy rainstorm accompanied by thunder and lightening. Thunderstorms often form from uplifting of warm air. The clouds associated with thunderstorms are cumulonimbus clouds. They have 3 stages: Developing stage Mature stage Dissipating stage