1. STRANGE
CLOUDS
(Chaps. 5 & 6)

4. Contrails

5. Contrails

6. p. 134

7. This enhanced infrared image from NASA's Terra satellite shows a widespread outbreak of contrails over the southeastern United States during the morning of January 29, Satellite data are critical for studying the effects of contrails. The crisscrossing white lines are contrails that form from planes flying in different directions at different altitudes. Each contrail spreads and moves with the wind. Contrails often form over large areas during winter and spring. CREDIT: NASA

8. Distrail (Dissipation Trail, Canal Cloud)

9. Hole Punch Cloud

11. © Vicki Harrison

12. Mountain Waves and Lee Waves (Lenticular)
Page: 161
FIGURE 6.24 Lenticular clouds that form in the wave directly over the mountain are called mountain wave clouds, whereas those that form downwind of the mountain are called lee wave clouds. On the underside of the lee wave’s crest a turbulent rotor cloud may form.

14. p. 161
Mark J. Madigan, Walsenburg, CO

15. Pileus

17. Pileus Formation

18. p. 132

19. Lenticular Clouds
FIGURE 6.25 Lenticular clouds forming one on top of the other
over the Sierra Nevada.

20. Lenticular Clouds

21. Lenticular Clouds

22. Lenticular Cloud

23. Lenticular Cloud
p. 132, 161
© Brian Holden

25. Cumulus Castellanus

26. Entrainment
Mixing of drier, cooler air along cloud edges. Can cause cloud droplets
to evaporate. Entrainment is greater with stronger rising motion in cloud.
p. 158

27. Cumulus Castellanus
p. 164–165

28. Mammatus

29. Pendules on Contrail

30. Mammatus

31. Mammatus

32. Mammatus

33. Mammatus
p. 132

34. Fractostratus (“Scud”)
p. 130

35. Fractostratus (“Scud”)

36. Virga

37. Virga
p. 179

38. Billows

40. Billows
Vertical Wind Shear
strong wind
weak wind
p. 164, 235

41. Billows
Page: 164
FIGURE 6.27 Billow clouds forming in a region where wind speed changes rapidly with altitude. This is a region of strong vertical wind shear. (More on the topic of wind shear and the formation of these clouds is given in Chapter 9, p. 235.)

42. Cloud Streets

43. Cloud Streets
STABLE
UNSTABLE
cold ice
warm water
wind

44. Cloud Streets
p. 164, 300