Aeceptable patterns at Bikini and Eniwetok are essentially only those which contain little northerly component at all levels and, for any substantial margin of safety in preventing contamination of inhabited islands to the east and southwest, must have some southerly component. Perturbations in the weather which provide these conditions at Bikini and Eniwetok are not long lived, and are not the dominent pattern. Acceptable patterns at Taongi include the flat hodograph plus, in mst cases, the inverted S to the north or south. In other words, it is possible to always fire at Taongi on the stable long lived weather pattern while at Eniwetok and Bikini, one can use essentially only the short lived pertucbations. The Joint Task Force SEVEN Meteorological Center at Pearl Harbor has recently published a report, under the direction of Commander Daniel A. Rex, USN., entitled "Climatology of Teongi". This report was prepared to compare, from a weather standpoint, the suitability of Taongi Atoll with the Eniwetok/ Bikini area as an atomic nuclear test site. This report has been studied in detail at UCRL by Dr. A. Vay Shelton, and others, and although there is not full egreement on the interpretations of Commander Rex's determinations, there is no question that Taongi offers some advantages. Three 15 day periods were analysed by the JIF 7 Group: 14 April - 28 April 1956 inclusive 11 June <= 25 June 1956 inclusive 9 July - 23 July 1956 inclusive Trese 45 days embrace the period of firing activity at Bikini during Operation Redwing. Hodographs for Taongi on each of the above days were interpolated from analysei Redwing flow charts. Neglecting fallout computations ard space/time variation studies has led Commnder Rex's staff to state: "In summry, 32 days were judged to be satisfactory for shooting et ‘Taongi although local fallout on the shot site would have been experfenced on 19 of these 32 days. During the same period, 7 days were judged to be satisfactory for Bikini." Pare 6 of the Joint Task Force Meteorological Center report states the following conclusions: "a. The local weather conditions at Taongi my be expected to be some- whet more favorable for air and test operations than at Eniwetok/ Bikini; 1.e., less reinfall, decreased shower activity, stronger and more constant surface tradewinds, etc. “bd. COPIED/DOE LANL Re The upper wind regimes at the tvo locations may be expected to be essentially the same; i.e., predominately east-west. Because of its more northerly latitude, stronger northerly components will usually be observed in the upper westerlies at Taongi and the strength of these upper westerlies will prevail leter into the summer season, Variations from year to year mey be expected to effect both locations in the same sense end approximtely the sexc extent. gous