READQUARTERS JOINT TASK FORCE SEVEN . li oo 12 June 1956 "BLACKFOOT ENIWETOK OBSERVED WEATHER FOR 12 JUNE 1956 AT DETONATION TIME 0626M Sea Level Pressure Free Air Surface Temperature . Wet Bulb Temperature 1012.5 mb Dew Point Temperature Relative Humidity Surface Wind . 81,19 77 @2°F 75 BOF 81,.0% 075° 10-14 knots Visibility 10 miles CLOUDS: 2/10 cumlus; estimated at 1500 ft. Large cumulus with shower activity located 74 miles bearing 060° from Fniwetok. Top of this cumulus measured by radar at 37,000 ft. , 1/10 stratocumlus; base estimated at 4500 ft. 2/10 or more altocumilus; estimated at 9000 ft. (opa — 8/10 cirrostratus; estimated at 30,000 ft. (thin)ras transparent) AREA WeATHER SUMMARY FROM AIRCRAFT REPORTS: _ 3/8-5/8 cumilus over Eniwetok area with bases at 1500 feet and tops ‘- generally at 5000-7000 feet. Cumulonimbus located south of GZ with top at 35,000 feet. Some cumlonimbus tops estimated at 45,000 feet to northeast and north of GZ (no distance estimated), A scattered line of cumlo- nimbus about 30 miles east of GZ with tops estimated at 40,000 feet. 8/10 altostratus; bases at 13,500 ft with tops at 15,000 feet. 8/10-9/10 cirrostratus (very thin); based at 30,000 feet which appeared to be "breaking up" and dissipating. Rain showers were observed to the east and west of GZ, no distances estimated, DNA STATE OF SEA: Ocean Side: oo Wave heights 5 feet, period 6 seconds, direction 090°. Lagoon Side: Wave heights less than 1 foot. ENTWETOK UFPER AIR SOUNDING (1117152) Pressure (Millibars) 1000 850 7L8 Height (Feet) 36h, 5,016 8, 530 Temperature (°C) 26.3 17.7 11.0 | Dew Point (°C) 23.6 13.3 Ob: a