area predictor and map scales must be the same.
b. Determine the yield group in which the estimated or actual yield lies.
Obtain effective windspeed and direction from data line of effective wind message for yield group selected.
d. Draw a line from center of azimuth dial through the azimuth (degrees) that corresponds to the wind direction
obtained in step (c) above Label the line GN (grid north).
e. Determine the downwind distance of Zone I from the area predictor nomogram (fig. 2) as follows.
(1) Locate a point on the YIELD (right-hand) scale corresponding to the estimated or actual nuclear yield. DO
NOT use yield group.
(2) Locate a point on the EFFECTIVE WIND SPEED (left-hand) scale corresponding to windspeed obtained
from effective wind message (c above).
Connect points located on the YIELD and EFFECTIVE WIND SPEED scales with a straight edge.
Read the downwind distance for Zone I at the intersection of the straightedge and the center scale.
Use the downwind distance of Zone I to