aboard after the midnight weather sounding and to be prepared to move south
at "best speed" in the event of fallout.
Based on the midnight weather forecast,
the surface and air radex
areas from H-hour to H+6 were:
Surface Radex.
True bearings from ground zero:
240°
clockwise to 70°, radial distance of 75 nmi (139 km);
270° clockwise to 80°, radial distance of 100 nmi (185
km).
Circular
radex area around ground zero of 30 nmi
(56 km)
Air Radex.
(12.19 km)
For H+l, 10,000 feet (3.05 km) to 40,000 feet
(true bearings from ground zero):
95° clock-
wise to 35°, maximum distance 10 nmi (18.5 km); 35°
clockwise to 95°, maximum distance 35 nmi
(65 km).
For H+l, 40,000 feet (3.05 km) and up (true bearings
from ground zero):
85° clockwise to 50°, maximum dis-
tance 25 nmi
(46.3 km); 50° clockwise to 85°, maximum
distance 60 nmi
(111 km).
For H+6, 10,000 feet to 40,000 feet (12.19 km) (true
bearings from ground zero):
90° clockwise to 45°, maximum distance 30 nmi (55.6 km); 45° clockwise to 90°, maximum distance 180 nmi (333 km).
For H+6, 40,000 feet (12.19) and up (true bearings
from ground zeto):
85° clockwise to 509, maximum dis-
tance 80 nmi (148 km); 50° clockwise to 85°, maximum
distance 290 nmi
(537 km).
The radsafe situation was recommended as favorable at the 0100
(26 April)
command briefing.
Since light surface winds were predicted
to move south, it was recommended that the task force ships
required to be closer for operational reasons) move 50 nmi
east of ground zero.
safe check at 0400.
{except those
(93 km)
south-~-
It was also decided to make a final weather and radThe forecast fallout was based on midnight weather,
using the method of elliptical approximations as shown in Figure 80.
A
new fallout prediction technique, based on time and space changes in the
wind pattern, was also used for UNION, and the results presented at the
command briefing.
The pattern was similar to that shown in Figure 80 ex-
cept that the mid-line was reported to be a little farther south
ence 16, Tab N).
286
(Refer-