4-43. Which of the following statements concerning skagerraking and occlusions is correct? 1. Skagerraking  occurs  most  frequently  on the west coast of mountainous continents 2. The new low develops very rapidly 3. Skagerraking can occur with either cold or warm occlusions 4. Each of the above 4-44. When  an  air  mass  leaves  its  source  region,  it may be modified by the underlying surface in which of the following manners? 1. Moisture may be added and taken away 2. Temperatures may be increased or decreased 3. Frontal characteristics may be completely destroyed 4. All of the above 4-45. In  the  western  Atlantic  and  Pacific  Oceans, cold  fronts  of  fall  and  winter  are  of  greater concern, to shipping than at other times of the year. Why? 1. Air   mass   contrast   is   magnified   thereby producing more severe weather 2. Gale force winds are common in the cold air to the rear of these fronts 3. Low-pressure  systems  are  often  spawned and   develop   over   the   warm   northerly flowing waters of these regions 4. All of the above 4-46. To be classified as rain, the water droplets that reach the Earth’s surface will have a diameter of 1. 001 to .01 inch 2. .005 to .02 inch 3. .010 to .02 inch 4. .020 inch and greater 4-47. How is precipitation that falls from convective clouds classified? 1. Rain 2. Snow 3. Showery 4. Steady 4-48. Which of the following hydrometeors appears as  a  fine  mist,  floats  rather  than  falls  through the  air,  and  is  frequently  accompanied  by  fog and restricted visibilities? 1. Light rain 2. Snow 3. Drizzle 4. Rain 4-49. Which  of  the  following  hydrometeors  is  con- sidered to be the frozen equivalent of drizzle? 1. Snow grains 2. Snow pellets 3. Ice pellets 4. Ice crystals 4-50. What is another name for sleet? 1. Snow grains 2. Snow pellets 3. Ice pellets 4. Ice crystals 4-51. How, if at all, does sleet differ from small hail? 1. Sleet rebounds on striking the ground, hail does not 2. Sleet  is  composed  of  snow  encased  in  an ice layer, and hail is the exact opposite 3. Sleet is a continuous type of precipitation, while small hail is showery 4. They are both ice pellets and do not differ 4-52. Hail forms in what type of cloud? 1. Cumulus mediocris 2. Altocumulus castellanus 3. Nimbostratus 4. Cumulonimbus 4-53. Which    of    the    following    hydrometeors    is common in polar regions and mainly visible in sunlight? 1. Ice prisms 2. Ice pellets 3. Snow pellets 4. Snow grains 4-54. What  occurs  when  water  droplets  in  a  cloud evaporate and then sublimate directly onto ice crystals within the cloud? 1. The ice crystals always melt 2. Precipitation begins 3. Nothing until the ice crystals melt, then the original droplets will have grown in size 4. Turbulence 23