The exact date for this information is unknown but it may be 1954.
|Air Mass||Source Region||Clouds||Ceiling||Visibility||Turbulence|
|cP||From Canada||Scattered afternoon CU||Unlimited except in or before showers||Good; a few patches of fog||Moderate up to 10,000 feet in afternoon|
|mP||From the Pacific over the Pacific coast||ST, tops 2000 ft to 5000 ft, frequent at night||100 ft to 2500 ft unlimited during day||Poor, especially at night||Slightly rough below and in clouds, smooth above|
|mP||From the Pacific east of the mountains||Scattered afternoon CU||Unlimited||Excellent||Generally smooth except in lowest layers in afternoon|
|mP||From the Atlantic||Broken to overcast SC||800 ft to 2000 ft||Good||Light below clouds|
|mT||From the Gulf and Atlantic||ST or SC in early morning; CU and CB in afternoon||Morning 500 ft to 1500 ft; afternoon 2000 ft to 4000 ft||Excellent except below clouds in early morning||Smooth in early morning, rough in afternoon|
|cT||From Mexico and the Southwest States||None||Unlimited||Excellent||Smooth in early morning, rough in afternoon|