HEADQUARTERS JOINT TASK FORCE SEVEN APO 437 San Francisco, California 21 May 1956 BIKINI OBSERVED WEATHER FOR 21 MAY 1956 CHEROKEE. DETONATION TIME 0551u Sea Level Pressure Temperature 1009.8 mb 819 Dew Point ‘73°F Relative Humidity 76% Surface Wind 140°, 10 kts Visibility CLOUDS: More than 10 miles 2/10 cumulus, bases 1600 ft, tops 2500 ft; 2/10 cirrus at 38,000 ft. WHATHPR: Very widely scattered showers, There were three showers in the vicinity of the atoll at shot time: one very light shower just to the scuth of TARE; one light shower, which was dissipating, near BRAVO; and a light shower east of NAN. 7 STATE OF SEA: : Bikini Lagoon: at anchorage, 2,5 ft. near Nam. Average of highest 1/3 of waves; 3.0 ft. The predominant direction of waves at anchorage was 1359; near Mam, 100°, waves; 4,0 ft. Open Sea: Average of highest 1/3 of The predominant direction of waves in open sea was 100°, SOUNDING Pressure Height iillibars Feet 1009 1000 916 . 850 835 823 772 716 710 - 700 500 153 Sfe 320 Temperature Dew Point 27.2 26.5 22,2 22.5 °¢ ‘ 4,930 , 18.5 15.5 15.2 - 13.5 17.5 10.8 09.5 13.5 06.2 02,2 10.5 10,230 19 ,O80 10.2 07.2 03.5 -07.8 -10.2 07.2 — °¢ =10.2 03.5 -14.5