se cist ceetate axis; and if the wind shear is greater than 120° then crattin Mitcerriiatl the fall-out area from the mushroom is circular, This ellipse would be centered at a point 7500 ft below the tep af the mushroom, and it will be referra. to as Ellipse A. Within Ellipse A draw 4 second elliptical area and call this Ellipse B. The major axis of Hllipse Bis 1/2 the major axis of Ellipse A, and the ratios of majer to minor axis for the two ellipses are the same. Fall-out Prom Stem Draw an elliptical area from ground sero to a point representing 25,000 ft msl level on the wind vector plot. The minor aris is 1/4 the major axis. This rec- tangular or elliptical area is called Ellipse ©, within Ellipse C draw Ellipse D starting from ground zero to en Diener ee a point representing the 20,000 ™ msl level on the Wind vector plot with minor axis 1/4 major axis. Similarly draw Ellipse E from ground zero to 15,000 ft mal level. Fall-out Connecting Stem and Mishroom Areas. The fall-out outside of the stem and mushroom areas cannot be drawn by any specified methods, However, the ———o general fall-out from ground zero sut to 150 niles appears to cover a pie-shaped area with an apex angle of 15 to 30°. It 1s recommended that this procedure pi be following in the construction of the fcrecast fall-out ¢ 23 B4g7 f ia AAR (7+) CUSSED 3eeitiiip