1. Bellwork 4/18 What is El Nino/La Nina?
What are some effects of El Nino/La Nina? Could be weather related, biological, economical, health related, ect…

2. “A cold front will be passing through our area over the next couple of days” A phrase that you’ve probably heard on a weather report (or something similar).

3. Air masses Characteristics 1600 km (1000 mi.) or more across
Large body of air
1600 km (1000 mi.) or more across
Perhaps several kilometers thick
Similar temperature at any given altitude
Similar moisture at any given altitude
Move and affect a large portion of a continent

4. A cold Canadian air mass

5. Source region – the area where an air mass acquires its properties
Classification of an air mass
Two criteria are used to classify air masses
By the latitude of the source region
Polar (P)
Tropical (T)
By the surface type at the source region
Continental (c)
Maritime (m)

6. Air masses are classified on the basis of their source region

7. Air masses Four basic types of air masses Continental polar (cP)
Continental tropical (cT)
Maritime polar (mP)
Maritime tropical (mT)

8. Which air masses affect the U.S?
cP and mT air masses are the most important air masses in North America
Continental polar (cP)
From northern Canada and interior of Alaska
Winter – brings cold, dry air
Summer – brings cool relief

9. Fronts Boundary that separates air masses of different densities
Warmer, less dense air forced aloft
Cooler, denser air acts as wedge

10. Types of Fronts Warm front Warm air replaces cooler air
Shown on a map by a line with semicircles
Slow rate of advance & small slope
Light-to-moderate precipitation

11. Cold front Cold air replaces warm air
Shown on a map by a line with triangles
Advances faster than a warm front & has a steep slope
Associated weather is more violent than a warm front
Intensity of precipitation is greater
Duration of precipitation is shorter

12. Stationary front
Flow of air on both sides of the front is almost parallel to the line of the front
Surface position of the front does not move

13. Occluded front
Active cold front overtakes a warm front
Cold air wedges the warm air upward
Precipitation is associated with warm air being forced aloft

14. Remember… This is an “Idealized” explanation
This is weather typical of various front types
Weather may or may not conform to these descriptions/pictures

20. Whiteboard Questions

21. Describe the Pressure Gradient Force.

22. Predict where is the air near Utah going to move.

23. Which direction do cyclones rotate in the Northern Hemisphere?

24. Which direction do anticyclones rotate in the Northern Hemisphere?

25. Are cyclones associated with a High or Low pressure system?

26. Which direction is wind coming from at the weather station in Minnesota?

27. Draw an “L” on your whiteboard
Draw an “L” on your whiteboard. Draw in arrows around the “L” to indicate where winds would be coming from.

28. Coriolis Effect deflects air the _____________ in the Northern Hemisphere.

29. Air is moving from Florida away from the equator
Air is moving from Florida away from the equator. Which direction will it be deflected?

31. How does a change in global wind patterns create El Nino conditions?

32. Describe an effect that El Nino has on an area’s Economy, Public Health, or Ecology