04/18/23

Warm up Activity• Warm up question: What is a wave cyclone

• Exit: What is the difference between a Hurricane and a Typoon

• Homework – Vocabulary page 518; define and give one fact. Due 2/27

– Review Questions page 501. Due 2/25

– Review Questions page 508. Due 2/26

04/18/23

Essential questionI will be able to compare the

characteristic weather patterns of cold fronts with those of warm

frontsHomework

1.Vocabulary page 518; define and give one fact. Due 2/27

2.Review Questions page 501. Due 2/25

3.Review Questions page 508. Due 2/26

Link

04/18/23

Chapter 25 section 1 Vocabulary: define and write sentences or pictures: page 518

1. Air Mass

2. Maritime Polar

3. Maritime Tropical

4. Continental Polar

5. Continental Tropical

6. Front

7. Cold front

8. Squall line

9. Warm front

10. Stationary front

11. Occluded front

12. Polar front

13. Wave cyclones14. Anticyclones15. Hurricane16. Typhoons17. Thunderstorm18. Tornado19. Waterspouts20. Bimetal thermometer21. Thermograph22. Electrical thermometer23. Wind vane24. Radar25. Station model26. isobars

04/18/23

Section 25.1Cornell Notes

• Air Masses • Form because warm air rises at the equators and cold air sinks at the poles. There are 3 convection cells in the Northern Hemisphere and 3 in the Southern Hemisphere.

• The Earth’s rotation and land masses cause wind to blow in different directions.

• In areas with small pressure differences, the air will stay long enough to develop a uniform temp and humidity. i.e. deserts, oceans, and polar areas.

04/18/23

Section 25.1Cornell Notes

• Types of Air Masses

• Classified by the source region; Polar is cold and labeled “P”, Tropical are warm and labeled “T”, Masses that form over land are continental and labeled “c”, Masses that form over oceans are maritime and labeled “m”.

• These air masses can stay over the source region for days but will move because of wind and the Earth rotation eventually.

04/18/23

Section 25.1Cornell Notes

• North American Air Masses

• Polar Air Masses

• Affected by seven regions, but the air can change as it moves away from it’s source region.

• 3 polar masses influence North America; continental polar Canadian (cP), maritime polar Pacific (mP), maritime polar Atlantic

• Canadian moves southeast off the Canadian ice into The United States and can moves as far south as the Gulf.

04/18/23

Section 25.1Cornell Notes

• Polar Air Masses • The Pacific air mass forms in the waters near Alaska. Very moist but not extremely cold, in winter they bring snow to the Pacific Coast and in summer fog. Most moisture lost crossing the mountains and bring dry weather to the Mid U.S.

• The Atlantic air mass normally moves off towards Europe, but sometimes in the winter brings cold cloudy weather to New England, in the summer cool and foggy weather.

04/18/23

Section 25.1Cornell Notes

• Tropical Air Masses

• 4 influence North America; Continental Tropical, maritime tropical gulf, maritime tropical Atlantic, and maritime tropical Pacific.

• cT comes from the Deserts of Northern Mexico and bring clear, dry and very hot weather.

• mT Atlantic and Gulf bring mild cloudy weather in winter and hot humid weather, thunderstorms and hurricanes in the summer.

• mT pacific rarely reach the coast, but in the winter can bring heavy rain and thunderstorms.

04/18/23

Chapter 25 section 2 Vocabulary: define and write sentences

1. Front

2. Cold front

3. Squall line

4. Warm front

5. Stationary front

6. Occluded front

7. Polar front

8. Wave cyclones

9. Anticyclones

10.Hurricane

11.Typhoons

12.Thunderstorm

13.Tornado

14.Waterspouts

Essential Question

• Compare the characteristic weather patterns of cold fronts and warm fronts

04/18/23

04/18/23

Section 25.2

• What is a Front

• What are the types of fronts

04/18/23

Section 25.2• Fronts

• Types of Fronts

• A boundary between

air masses• Cold Front – Cold air overtakes warm

air and lifts the warm air – a squall line forms on this front

• Warm Front – Warm air overtakes cold and rises in a gradual slope

• Stationary Front – is when the air masses are not displaced

• Occluded Front – is when a cold front push the warm air completely off the ground

04/18/23

Section 25.2Cornell Notes

• What are Polar Fronts and Wave Cyclones

04/18/23

Section 25.2Cornell Notes• Polar

Fronts

• Wave Cyclones

• A Polar front circles the earth at 40 to 60 degrees latitude in both hemispheres.

• In winter it is in the Middle of North America .

• In Summer it is North of the Great lakes• The boundary along a polar front is

where wave cycles form. They can grow to 2,500 km in diameter, with winds that blow in an upward circle path around the low pressure center. They have major influences on our weather.

04/18/23

Section 25.2• What are the Stages of a Wave

Cyclones

• What is an Anticyclones

04/18/23

Section 25.2• Stages of a

Wave Cyclones

• Anticyclones

• Stage one there is a stationary front, the winds move parallel to the front in opposite directions.

• Stage two an intensifying low pressure region develops along the front, bringing stormy weather.

• Stage three last about 24 hours and continues to move east in North America. The process can restart.

• The anticyclone spins clockwise and brings dry warm air to a region or fair weather. The air is sinking

04/18/23

Section 25.2Cornell Notes

• Hurricanes• Has winds over 120 km/hr• No more then 700 km in diameter• A storm starts with warm moist air

evaporating from the ocean rapidly• The release of latent heat increases

the rise of air• Winds increase towards the eye• The eye is clear and calm• The danger is due to raising sea levels

and large waves.

04/18/23

Section 25.2• Thunderstorms • Lightning, thunder and strong winds

accompany this type of storm.• High surface temperatures cause the

rapid rise of warm moist air.• In stage one a Cumulus clouds form

or Cumulonimbus.• Stage two is called the mature stage

and is when the storm becomes dark cumulonimbus cloud with heavy torrential rains

• The final stage or dissipating is when the storm has used the available water vapor and the winds end.

04/18/23

Section 25.2• Tornadoes

• Are the smallest, most violent and shortest lived severe storms.

• Starts when a thunderstorm meets high altitude horizontal winds.

• This may form a narrow, funnel shaped, rapidly spinning extension that may move downward to the ground.

• Not more than 100 m wide, path is destroyed.• Winds can reach 400 km/hr• Most common in an area called tornado alley in

the United States.• When they form over water they are called

waterspouts and usually weaker.

04/18/23

Chapter 25 section 3 Vocabulary: define and write sentences

1.Bimetal thermometer

2.Thermograph

3.Electrical thermometer

4.Wind vane

5. radar

04/18/23

Section 25.3• Weather

Instruments

• Measuring Air Temperature

• Barometers, psychrometers, rain gauges, thermometer, anemometer, radiosonde and radar

• Celsius and Fahrenheit used in the United States.

• 3 types of thermometers– Liquid use Mercury or Alchol to

determine the temperature– Bimetal that expand or contract to

temperature, a thermograph measures the temperature change

– Electrical use the flow of electric current through certain materials

04/18/23

Section 25.3• Measuring

Wind Speed and Direction

• Measuring upper-atmospheric conditions

• An anemometer measures in m/sec, MPH, or knots.

• A wind vane tells you the direction the wind comes from. The points into the wind.

• A radiosonde is attached to a helium filled balloon to measure weather conditions in the upper atmosphere

• Radar can also be used to detect water droplets, Doppler can even give direction

• Satellites can also be used to measure cloud. Land and sea temperatures.

04/18/23

Chapter 25 section 4 Vocabulary: define and write sentences

1.Station model

2.isobars

04/18/23

Section 25.4• Forecasting

the weather • History – more then 4,000 years of

trying to predict the weather• The invention of the thermometer

and barometer made forecasting possible

• In 1844 the telegraph made it so data could be shared quickly

• 1870 the U.S. formed the Weather forecasting agency, renamed the National Weather Service

• Data is collected from around the world every 6 hours

04/18/23

Section 25.4Cornell Notes

• Making a Weather Map

04/18/23

Section 25.4

04/18/23

Section 25.4• Types of

forecasting

• Controlling the weather

• Two types daily and long term• Daily – weather for the next 24

hours – local daily can be as much as 5 days

• Long range forecast covers monthly & seasonal outlooks

• Cloud seeding has been used to reduce the intensity of storms with limited results.

• Some experimentation still continues.