Air Masses and Weather Maps: Arrows and Scale Visualization

1. Day 47 Investigation 9 part 2 Air Masses and Weather Maps

2. Arrows and Scale Visualization Exercise 9.1

3. Resources P. 85

4. Resources P. 85

5. Color and Real vs Diagram Visualization Exercise 9.2

6. Resources, P. 89

7. Review Air Masses • Air masses: • Large thick bodies of air • Uniform in temperature and humidity • Have distinct boundaries • Cover large areas of earth’s surface • Reach top of the troposphere • Names for the source region

8. Cold air masses from the polar regions move south and east Colliding Air Masses Air masses don’t stay in one place Warm air masses from the tropics move north and east

9. Colliding Air Masses Air masses don’t stay in one place Movement of air masses creates opportunity for air masses of different temperatures and humidity to collide

10. Meeting of Air Masses • Remember the density bottles • What is going on inside of the bottle? • Denser liquid below the less-dense one

11. Meeting of Air Masses • Imagine • I reach north • Grab a cP (continental polar) air mass • Shrink it • Jam it into the bottle cP

12. Meeting of Air Masses • Imagine • I reach south • Grab a mT (maritime tropical) air mass • Shrink it • Jam it into the bottle with the cP one • What happens to the air masses? • Polar air sinks because it is denser • Tropical Air lifts to the top because it is less dense mT cP

13. Gases and liquids have fluid movement The liquid in the bottle represents what would happen in real life with air masses Air Mass Model

14. Fronts • If air masses meet, a boundary forms • Front • A boundary between two air masses

15. Origin of “Fronts” • Originated after World War 1 • Norwegian meteorologists • The zone where 2 opposing armies clash is called a battlefront • The boundary - violent weather changes often occur

16. Naming Fronts • Takes the name of the air mass that is moving faster and overtakes a slower air mass

17. Cold Fronts • A boundary that forms when a cold air mass overtakes warm air mass Clouds form Cold, dense air plows under warm, less dense air Warm, humid air rises and cools

18. Weather and Cold Fronts • Effects from cold fronts happen quickly • Clouds form, can grow into thunderstorms • Rain or snow can fall • Lightening and hail • Drop in temperature • Pressureincreases A cold front moves in Cold front symbol on weather map

19. Warm Front • The boundary that forms when a warm air mass overtakes a cold air mass Can be hundreds of km long Warm air slides up over cold air at a gentle slope

20. Weather and Warm Front A warm front moves in • Effects happen over long period of time • Air pressure decreases • Temperature rises at thesurface • Clouds thicken and lower(first wispy, cirrus clouds) thenothers (cumulostratus,altostratus, nimobostratus,stratus, possibly fog) • Rain, snow, sleet or freezingrain begin to fall Warm front symbol on weather map

21. Surface Observations • Meteorologists receive weather observations from stations all over the United States and the world • These are called surface observations

22. Surface Observations • Surface Observations include: • Temperature • Humidity • Air Pressure • Wind Speed and Direction • Cloud Cover and Type • Precipitation Type and Amount

23. Look at Weather Symbols • Use special codes or symbols to represent weather data on a map • Typical weather symbol

24. Weather Symbol From which it is blowing Short barb = 5 knots Long barb = 10 knots

25. Surface Observations • Programmed into a computer that plots the information on a map • Used by meteorologist to make weather predictions

26. Practice Reading Weather Maps • Open to page 57 of your lab book and see if you can read a weather map.