EAW. Atmosphere and Weather Benchmark 3

Explain and predict general weather patterns

and storms.

What is an air mass?

A giant bubble of air with the same temperature and humidity throughout

Earth’s surface

Air masses get their characteristics from the location where they form.

.

• mT – maritime tropical – warm, moist air• mP – maritime polar – cold, moist air• cT – continental tropical – warm, dry air• cP – continental polar – cool, dry air

1

2

3

4 5

Name the type of air mass is shown at each of the following locations:

Location 1: mP

Location 2: mT

Location 3:

Location 4:

Location 5:

cP

cT

mT

What is a front?

the boundary between 2 different air masses

front

Earth’ surface

warm, moist mT air cool, dry cP air

cP air

mT air

Cold Fronts = storms

• thunderstorms, lightning, and severe weather

• heavy rainfall

• pass quickly

• hail, high winds, and/or tornadoes possible

Cold Front

A

B

After a cold front passes you can expect…

• Cooler temperatures

• Clearer skies

• Fair weather

• Drier air – lower humidity

• Higher pressure

• Rising barometer

mT air

cP air

Warm Fronts = overcast skies

• Hours to days of gray, overcast skies• On and off rain gentle rains• Pass slowly• NO SEVERE WEATHER!!!

http://images.usatoday.com/weather/photos/lowpres2.jpg

Stationary Fronts

Key concepts: Weather patternscold front, warm front, stationary front, air mass, high and low pressure systems.

Storms—thunderstorms, lightningand thunder, tornadoes, hurricanes, winds, blizzards.

Buoyancy, thermal expansion, convection. See(thermal expansion) and (density).

Weather maps - show fronts, temperatures, isobars, etc.

thermometer – measures air temperature

hygrometer – measures relative humidity

barometer - measures air pressure

anemometer - measures wind speed

wind vane – determines the direction of the wind

rain gauge – records the amount of rainfall

Satellite radar monitoring

Weather Tools:

Real-world contexts: Observable daily weather patterns

Examples of weather reports from TV,radio, newspapers, including representations on

weather maps.

Reports of local weather patternsinfluenced by the jet stream and prevailing winds.

Resources• http://www.uwsp.edu/geo/faculty/ritter/images/atmosphere/pressure_wind/

low_pressure_small.jpg

• http://www.traveleye.com/northamerica/images/map.jpeg

• http://www.islandnet.com/~see/weather/graphics/photos/naairmass2.jpg

• http://members.aol.com/pakulda/images/stpptam.gif