ohana Since all tests were conducted at dawn, 30 minutes prior to occurred. sunrise, definitive pre-test visual weather observations were difficult to obtain. However, careful observations were made to ascertain cloud amounts through observations of stars and, when possible, optical phenom— ena such as lunar halos and coronas. 5. Photographs of the nuclear clou3. The weather and assosiates cloud cover can be better visualized-by an inspection of the aerial photographs made at and subsequent to each of the detonations, Much useful informtion is available and certain conclusions can be made from an examination of these photographs. Consequently, a more realistic deduction can be made of the effects of high yield detonations upcn the weather. ix 2001540