1. Understanding Weather

2. Weather The condition of the atmosphere at a certain time and place The condition of the atmosphere at a certain time and place

3. TOOLS Anemometer Used to measure wind speed Used to measure wind speed

4. Barometer Used to measure air pressure Used to measure air pressure

5. Radar (Hurricane Ike)

6. Weather Balloons

7. psychrometer An instrument used for measuring relative humidity. It has one “dry” bulb and one “wet” bulb. An instrument used for measuring relative humidity. It has one “dry” bulb and one “wet” bulb.

8. Air Masses A large body of air that has the same temperature and moisture A large body of air that has the same temperature and moisture Get their moisture and temperature from the area over which it forms Get their moisture and temperature from the area over which it forms

9. Air Masses

10. Fronts Boundary between two air masses Boundary between two air masses Bring changes in the weather Bring changes in the weather Fronts are named for the air that is behind them Fronts are named for the air that is behind them

11. Cold Front Cold dense air pushes warm air out of the way Cold dense air pushes warm air out of the way Moves quickly Moves quickly Brings short periods of heavy rain/thunderstorms/snow Brings short periods of heavy rain/thunderstorms/snow Lower temperatures are behind the front Lower temperatures are behind the front SYMBOL – the direction of the “arrows” points towards the direction the front is MOVING SYMBOL – the direction of the “arrows” points towards the direction the front is MOVING

14. Warm Front Warm air moves on top of the cold air mass, as it slowly pushes the cold air Warm air moves on top of the cold air mass, as it slowly pushes the cold air Moves slowly Moves slowly Brings many days of steady precipitation Brings many days of steady precipitation Higher temperatures and clear skies are behind the front Higher temperatures and clear skies are behind the front SYMBOL – direction of “half-moons” is the direction the front is moving SYMBOL – direction of “half-moons” is the direction the front is moving

17. Stationary Front The air from the warm front and cold front meet, but do not move The air from the warm front and cold front meet, but do not move Cold air mass cannot force warm air mass up Cold air mass cannot force warm air mass up Bring many days of steady precipitation Bring many days of steady precipitation SYMBOL – warm and cold fronts are moving in opposite directions, thus making a stationary condition SYMBOL – warm and cold fronts are moving in opposite directions, thus making a stationary condition

20. The End