aboard after the midnight weather sounding and to be prepared td nove south
at "best speed" in the event of fallout.
Based on the midnight weather forecast, the surface and air
areas from H-hour
fadex
to H+6 were:
Surface Radex.
True bearings from ground zero:
2409
clockwise to 70°, radial distance of 75 nmi (139 km);
270° clockwise to 809, 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 959, maximum distance 35 nmi (65 km).
For H+l,
40,000 feet
from ground zero):
tance 25 nmi
(3.05 km)
and up (true bearings
85° clockwise to 50°, maximum dis-
(46.3 km); 50° clockwise to 859, maximum
distance 60 nmi
(111 km).
For H+6, 10,000 feet to 40,000 feet
bearings from ground zero):
mum distance 30 nmi
(12.19 km)
{true
90° clockwise to 45°, maxi-
(55.6 km); 45° clockwise to 90°, max-
imum distance 180 nmi
(333 km).
For H+6, 40,000 feet (12.19) and up (true bearings
from ground zero):
85° clockwise to 50°, 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 predifted
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.
(exce
those
(93 km)
south-
It was also decided to make a final weather
[and rad-
The forecast fallout was based on midnight wether,
using the method of elliptical approximations as shown in Figure 8%.
new fallout prediction technique, based on time and space changes
[In the
wind pattern, was also used for UNION, and the results presented aq
command briefing.
A
the
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
(Hefer-