No changes were made In the forecast since the weather Si%llationhad
been developing as had been anticipated~t the Peter fillayminus 3 daY
briefi~
{
At the 11OOH briefing on Peter X--
D~ minus one, (7 April), the
forecast of expected cloud conditions was not changed. The wind prediction wae altered slightly to indicate that a somewhat greater decrease
,
in velocity w~s expected during the next 24 hOUIW. It VaS further
stated that the winds in the lower levels were expected to continue
light and vari6ble. This wind situation imposed a marked radiological
and from the radiologicalpoint of view, was not acceptable for
kard
an operatio%
At the 1600M briefing, the weather forecast was again altered
slightly to indicate a great amount of cloudiness. This change wke
based largely on the reports of the weather reconnaissanceaircraft
which indicated that the amount of cloudiness associatedwith the pressure
trough was greater than originally forecast. Accordingly, the peter
XAlay minus 3 day forecaet was amended by adding 3 tenths middle clouds
and lowering the base of the cirrus clouds from 34,000 to about 30,000
feet.
Since showers at the time of the explosion, especially if the showers
were to”occur over the zero point, would jeopardize some of the experiments
for measuring the various phenomena associated with the explosion,the
radar plan for observimg the presence, the development end,migration of
local showers,was eqlained at this briefing. The plan called formab
Ing maximum use of ship and aircraft r~rs
23
SEOTIOZTXI1 ‘
for spottingamd trackingall