1. CLOUDS

2. * Form of condensation * Visible chunks of small water droplets or ice crystals * Good indicators of what’s going on in the atmosphere

3. Conditions necessary for clouds to form 1. Condensation Nuclei – small, solid particle in the atmosphere that provide a surface that water vapor can condense on. (smoke, dust, ice) 2. Saturated air at its dew point

4. Convective Cooling (Adiabatic Cooling) Air rises and expands. This cools the air below the dew point and it condenses.

5. Forceful Lifting Air is forced upward when it hits a slope. It rises, expands, cools and condenses into a cloud.

6. Temperature Change Two air masses mix and cool below the dew point and condense.

7. Classified by form and altitude Root names: Cirrus: feathery/fibrous Stratus: layered Cumulus: piled up Alto: middle Nimbus: rain

8. Stratus Flat base Very low Cover large areas May block sun Very little precipitation

11. Nimbostratus Large, thick, grey patches Block out sun Continuous rain or snow Storm clouds

14. Altostratus Thin, gray fibers Sun shines through Rain or snow of long duration.

17. Cumulus Fluffy cotton balls White tops & dark bases. Fair weather

20. Altocumulus Flat bottomed gray/white Begin at middle altitude Possible rain & storms

23. Stratocumulus Low, lumpy layer Forms as rolls or waves

26. Cumulonimbus Anvil shape at top Dark base T-storms & heavy rain/possible hail. Summer clouds.

29. Cirrus Delicate Wispy, feathery Tiny ice crystals Fair weather clouds.

32. Cirrocumulus thin, white rippled layers tiny ice crystals mackerel sky fair weather thicken if storm’s coming...

35. Cirrostratus tiny ice crystals shapeless white veil “milky,” do not block sun rain within 24 hrs

38. CONTRAILS

40. KELVIN-HELMHOLTZ: caused by winds being deflected up & over a barrier (such as a mountain), causing a wave-like cloud structure

42. LENTICULAR: form downwind of an obstacle in the path of a strong air current.

44. MAMMATUS: sinking air within a cloud

46. Radiation Fog Ground cools off at night Air touching ground becomes cooled to the dew point and condenses “Burned away by sun as it warms up

47. Advection Fog Warm, moist air moves over a cool surface and forms a thick fog Common along coasts

48. Upslope Fog Humid air rises up an incline cools off and condenses into fog.

49. Steam Fog Shallow layer of fog Forms when cool air moves over inland warm body of water