FEB i4 "94
id:id
FROM KAMAN SCIENCES CORP
TO 17@22950154
PAGE . G44/R85
<a
e. A critical problem in predicting fall-out in-~
volves forecasting the stability or lack of stability of the
wind pattern after snot time. Since radicactive particle tra-
vel is determined primarily by the winds at each level, it is
required that winds must be fram favorable directions or varying within the outer limits on favorable directions during the
time of fallout. The critical fallout period was considered to
be on the order of twelve to sighteen hours for significant
fallout to occur. The variation in time arises from considera-
tions of wind shear, with more diffuse and less significant in-
tensitias at a given time associated with large angniar and
speed shear. For this reason, it was required that actual wind
observations and forecasts immediately before shot time and
throughout shot day be continuously considered in their relation
with the forecast conditions for. the first twenty-four hours
after the shot.
5.
PRE-SHOT BRIEFINGS:
the pre-shot cammand briefings:
a
The following were presented at
Weather
Weather conditions during the five days prior to
BRAVO indicated a favorable trend for BRAVO day with easterly
winds below 15,000 feet and winds of a southerly componant
abovee The situation presented at H-6 hours for the subsequent
2é hour period (18 hours after shot time) was satisfactory. The
24 hour period to begin 18 hours after shot time was predicted
to give an unfavorable trend as northwest winds were forecast
for the 10,000 to 20,000 foot levels.
be
RadSafe
(1) Resultant wind diagrams including latest
observed winds and forecast winds for H Hour and the 72 hour ©
cloud trajectories, which gave a fallout pattern in a narrow
sector to the east northeast and-a wide (1409) sector to the
south with very slow resultant winds. (See Figure 1). ga. +.
on oN,
Figure 2).
(2) Surface radex, H to H plus 6 houxiee (See
:
(3) Outlooks for:.
{a) Bikini:
Unfavorable; Eniwetok: Favorable;
Ujelang: Favorable, and the native pomlated avolis in southeast
quaarant from ground zero favorable, since resultant winds in
the direction of these areas were considered too slow to move
Significant fallout to tha atolls involved.
(b) Task Force fleet: Favorable, provided
ships moved out at least 50 miles.
3