9-63. Atlantic mTw air moving northward over a 9-65. Low stratiform clouds in the morning, 



land surface in winter is characterized convective clouds during the day, and 



by the nighttime occurrence of frequent thunderstorms at night are typi- 



1. fog and stratus clouds cal conditions of the east coast of the 



2. cumuliform clouds United States in summer and are the 



3. thunderstorms result of the predominance of 



4. showers 



1. 



mT air 



2. 



mP air 



3. 



cT air 



4. 



E air 



9-64. During winter, all of the following 

 types of air masses are found over 

 continental North America except 



1. S 9-66. What is the hottest air mass on record? 



2. cT 1. Australian cT 



3. mT 2. North African cT 



4. cPk 3. South American E 



4. Southeast Asian mT 



57 



