On October 19, 1962, the Central Intelligence Agency released another "Joint Evaluation of Soviet Missile Threat in Cuba" (see Document 30) for the initial evaluation. The new evaluation was based on intelligence as of 8 p.m. on October 19. It included Iron Bark material and was based on "relatively complete photo interpretation" of four of the six U-2 missions of October 17 and part of the final two missions.
This evaluation discovered an additional regiment of Soviet 1020-nm (SS-4) missiles at two sites east of Havana in the Sagua La Grande area that appeared to be more permanent than the two sites already identified at San Cristobal in western Cuba. This evaluation predicted that the two 2200-nm (SS-5) sites in the Guanajay area near Havana could be operational within 6 weeks and by December 15-30, respectively. Although there was still no evidence of currently operational nuclear storage facilities in Cuba, there was evidence that a site was under construction near Guanajay. The evaluation suggested that the assumption that nuclear weapons were already in Cuba still held true. The evaluation also suggested that the 1020-nm missiles would probably be equipped with 2 to 3 megaton warheads and the 2200-nm IRBM's with 3 to 5 megaton warheads. The significance of the new intelligence in this evaluation was that it indicated that the Soviet military buildup in Cuba was being carried out on an "urgent basis" on a pattern of deployment "calculated to achieve quick operational status and then to complete site construction." An extract is reproduced in CIA Documents on the Cuban Missile Crisis, 1962, pages 203-208.
In addition to the two evaluations, nine supplements were prepared. Supplement 1 was as of 10 p.m. October 20; supplement 2 was as of 10 p.m. October 21; supplement 3 as of 10 p.m. October 22; supplement 4 as of 1 a.m. October 24; supplement 5 as of 10 p.m. October 24; supplement 6 as of 2 a.m. October 26; supplement 7 as of 2 a.m. October 27; supplement 8 as of 2 a.m. October 28; and supplement 9 as of 10:20 p.m. October 28. The two evaluations and the annexes covered the immediate crisis. Extracts of the supplements are all ibid., pages 227-234, 261-262, pages are all ibid., pages 227-234, 261-262, 281-282, 293-294, 299-301, 313-314, 323-325, 337-340, 349-350, respectively.