1. Weather Patterns CH. 13

2. Weather vs. Climate Weather: current state of the atmosphere Climate: average weather of a particular area over a long span of time

3. Air Masses Air mass- huge body of air with similar temperatures and moisture – Brings different weather to an area, lasts for several days, are classified 2 ways: http://player.discoveryeducation.com/index.cfm?guidAssetId=2C AB90DA-3C54-49D0-9847- AFACFBFD90CA&blnFromSearch=1&productcode=US

4. Classified how??? 1.By their temperature -Polar (P) -Tropical (T) 2. By the source region over which they form. -Continental: forms over land -Maritime: forms over water

5. Can you identify the air masses?

6. Air Masses and US (us or U.S. or both?) Most of US is affected by 2 air masses Continental Polar (cP) – begins in Canada and Alaska - cold and dry, little moisture, clear skies, lake effect snows Maritime Tropical (mT)- begins in Pacific or Atlantic Ocean - hot temps, lots of rain, unstable air, lots of humidity

7. How does cP affect Michigan in the summer? How does mT affects states like Florida and Louisiana in the winter?

8. Minor Roles… mP- occur in winter, bring lots of snow, come from the Pacific or the Atlantic cT- start in Mexico/SW US, least influence of all air masses What hot dry arid states are affected by cT?

10. Bell Ringer 1-4-2012 Determine the type of air mass that typically plays a role in the weather in your area. Describe the type of weather that is commonly associated with the air mass and where the air mass originates. Describe the season in your area which result from that air mass. (Looks somewhere around pg. 302 and 303 ) No you do not have to write this if you write in complete sentences!

11. Bell Ringer: January 6, 2012 Weather is a great metaphor for life - sometimes it's good, sometimes it's bad, and there's nothing much you can do about it but carry an umbrella. ~Terri Guillemets What do you think about this quote? Is it true? Why/ why not?

12. Fronts A front forms when 2 air masses meet The 2 fronts usually move at different speeds. There are 4 types: 1.Cold2. Warm 3.Stationary4. Occluded Extra: Big diff b/w air masses causes dramatic weather when fronts form

13. Warm Fronts Warm air moves into an area with cooler air A red line on the weather map: Symbol = Temperature difference (Temp Δ) at boundary Moves slowly, produces rain over a large area for an extended period Clouds = cirrus, cirrostratus, altostratus, nimbostratus Weather gets slowly warmer with light rain and wind

14. Warm Front moving in! http://www.youtube.com/watch?v=4QPkjP7EzaI

15. Cloud Types

16. Cold Fronts Cold, dense air moves into an area occupied by warmer air. A blue line on the weather map: Symbol: A steep face advance rapidly Heavy downpours, gusty winds, violent weather, cumulonimbus clouds move quickly Calmer weather follows.

17. Cold Front video! http://www.youtube.com/watch?v=0NoPXm7d5Tc (Colorado) http://www.youtube.com/watch?v=0NoPXm7d5Tc Better Cold Front Video! http://www.youtube.com/watch?v=nPFMKw1_wKM (Latvia) http://www.youtube.com/watch?v=nPFMKw1_wKM

18. Stationary Fronts Fronts are not overtaking, but rather moving parallel to each other; don’t really move… stationary! Red & blue on the weather map: symbol? Extra: Very little “weather” happening if stationary for a short time. If stationary for a long time, warmer weather will occur

19. Occluded Fronts Cold front overtakes a warm front Complex weather patterns- CRAZY! And unpredictable Fronts, much like all of nature, do not always behave as we would expect (they may produce weather that varies from our descriptions)