Time-of-arrival arcs of interest are drawn in, using the effective wind

speed and the procedure in Part A.

Next, the fallout predictor ground zero point is placed over the actual or

assumed GZ on the map, and the entire fallout predictor is rotated until the

effective downwind direction in degrees on the azimuth dial is pointing

toward grid north. The scale of the M5A2 Fallout Predictor and the map must

be the same.

The simplified fallout prediction is now complete, and

the

operational

aspects of the fallout hazard can be evaluated.

a. Infrequently, the fallout wind vector plot prepared by the NBCE may

indicate a warning area angle greater than 40 degrees. In these instances,

the greater angle will be given beside the particular line of the effective

downwind message for the yield group affected. Using units will expand the

warning area beyond the fixed 40-degree angle of the simplified fallout

predictor to correspond with the angle given at the side of the particular

line of the effective downwind message.

b. A special case may arise when one or more of the data lines on the

effective downwind message may contain only three digits. The three digits

are the Zone I downwind distance for the highest yield in the yield group of

interest and an effective wind speed of 8 kmph, determined from the nomogram

(Figure 3-14).

The example problem (below) illustrates the use of the M5A2 Radiological

Fallout Area Predictor in the preparation of a simplified fallout

prediction.

Assume that the S3, 2d Bn, 62d Inf, has the following effective downwind

message available: