plot on an illuminated transparent Combat Information Center plotting board was used for briefing, arid proved highly successful. d,; As a result of a favorsble upper wind trend from H minus 3O Acurs until. H minus 6 hours briefing, and a minimum shower probability, although the wind velocivies decreased appreciably, a favorable fall-out forecast was inde at the H minus 6 hours Commander's conference: (L) The very heavily radioactive lower portion of the borb cloud stem (0-15,000 feet) with debris, induced radioactive material, and unfissioned material was forecast to fall in a SURFACE HADES. with a DRIF? CONE oxbending from 200° to 260° true, with a radial distence of 20 miles, Fall-cut of significance as a health hasaird was oxpected to occur only on uninhabited islands wost of sero point. (2) Using fall-out data from "DOG" shot end res ultert wind plots fer significant levels from 30, 000 to 45,000 Poot, parbicles from 60 to 150 microns in diameter, with fell-out times of H plus 1. Lo 3.0 hours, were forecast bo be doposited out to about 4 te 4 miles to the southeast, With a eenerous six (64) mile radius for diffusion and dispersion, it was sbated that very minor fall-out might occur as far soith as PARHY ISLAND, The atomic cloud mushroom was forcenst to reach the tropopause dovel and to move casterly, (3) Vall-out wac cssontislly as forecast, although no detectable amounts reached inhabited islands - PIIRAAL ISLAND (7 miles away) was the farthest southeast that detectable fall-out occurred, The mushroom did reach the tropopause and moved. generally o.sterly. Restoration of normal eperations, other than scheduled project trips, was purposely delayed on "EASY" shot for about six (6) hours rather than the one hour period wed on "DOG" shot, ee Other RadSafe phases wore normal. RadSafe operational data wos available in satisfactory quantity and quality at the OCC, suitable for immediate use as required, - This utilised cxper- ence from "DOG" shot, durins which corresponding time, such data were not readily available at the occ, vty Beng