Air Masses and Fronts SWBAT explain the ways that air masses and fronts form; discuss the causes of severe weather; explain how technology is used to monitor and predict weather

Air Masses  Air mass –a large body of air that develops over a particular region of Earth’s surface.  Front –a boundary where air masses of different temperatures meet

Fronts  Cold Front –A cold air mass advances and pushes under a warm air mass, forcing to rise. –Can produce bands of violent storms

Fronts  Warm Fronts –Warm air advances into a region of cold air, and slides up over the colder air –Creates wide areas of precipitation

Fronts  Stationary Front –A warm and cold air mass meet, but neither advances –Can remain in the same location for days –Cloudiness and precipitation occur along the front

Fronts  Occluded Fronts –A fast-moving cold front overtakes a slower warm front and pushes it up, running into another cold front –Can produce cloudy weather and precipitation

High and Low Pressure Centers  Get your lab notebook  Title: Creating a Low-Pressure Center  Watch the demonstration  Answer questions 1 and 2, under analyze on page 359

Severe Weather  How do thunderstorms develop? –They usually develop around cold fronts where air is rapidly pushed upward –Cumulonimbus clouds form causing water droplets to fall into lower droplets and grow large –As the large droplets fall they cool the surrounding air creating downdrafts and strong winds –Cumulonimbus clouds also create lightning and thunder

Severe Weather  Tornado –a violent, whirling wind that moves in a narrow path over land.  Hurricane –a large storm that begins as an area of low pressure over tropical oceans.

With a partner  Answer question 1-5 on page 362  Be sure to answer in complete sentences.  Finish for homework.