But the screenshot you posted says 30-45 days not 14 days
And you are correct, Chris. As near as I can figure, lack of caffeine and sleep generated a conflation of this with a later DoD study. The general tone of optimism about MAJESTIC caused me to skip over that last sentence in the main paragraph when it came time to posting the attachment.
So on the question of timelines, the 1946 Army study is at variance with the 1985 DoD study of MAJESTIC (and the typhoon's impact on it) cited by
@Matt Wiser. It does, however, raise the question, which Skates does not discuss, of how an X-Day pushed back to the Dec. 1-15 timeframe, would still have been viable given how weather conditions off Kyushu typically deteriorate by that point. In fact, if I am not mistaken, Chris, you
criticized Giangreco in The Red's timeline thread for relying on the 1946 Army study without even mentioning the more optimistic 1985 DoD study. It would seem that the same criticism could be levelled here at John Ray Skates. It seems hard to believe that neither Giangreco or Skates were utterly unaware of it, so it remains a puzzle to me.
In fact, Giangreco sticks with the 45 day delay estimate in
a lecture he gave at the University of Kansas in 1998 - and again, without exploring whether mid-December weather would have forced a long postponement:
The Divine Wind, or Kamikaze, of a powerful typhoon destroyed a foreign invasion force heading for Japan in 1281, and it was for this storm that Japanese suicide aircraft of World War II were named. On October 9, 1945, a similar typhoon packing 140-mile per hour winds struck the American staging area on Okinawa that would have been expanded to capacity by that time if the war had not ended in September, and was still crammed with aircraft and assault shipping- much of which was destroyed. US analysts at the scene matter-of-factly reported that the storm would have caused up to a 45-day delay in the invasion of Kyushu. The point that goes begging, however, is that while these reports from the Pacific were correct in themselves, they did not make note of the critical significance that such a delay, well past the initial - and unacceptable - target date of December 1, would have on base construction on Kyushu, and consequently mean for the Honshu invasion, which would have then been pushed back as far as mid-April 1946.
If there had been no atom bombs and Tokyo had attempted to hold out for an extended time- a possibility that even bombing and blockade advocates granted- the Japanese would have immediately appreciated the impact of the storm in the waters around Okinawa. Moreover, they would know exactly what it meant for the follow-up invasion of Honshu, which they had predicted as accurately as the invasion of Kyushu. Even with the storm delay and friction of combat on Kyushu, the Coronet schedule would have led US engineers to perform virtual miracles to make up for lost time and implement Y-Day as early in April as possible.
Having said that, this also underlines (to me, at least) how Giangreco generally takes a somewhat more pessimistic view of DOWNFALL's prospects than Skates (or for that matter, Richard B. Frank) does. I am unable to resolve the analysis of the 1946 and 1985 studies (since I have not even read them) to offer a conclusion about which was closer to the money. And of course we would also need to look at the historical weather off Kyushu in November and December 1945 to know what actually would have happened with a November 15 or a December 15 X-Day - something I have not done, either.
I am reminded, by the way, that The Red opted for the 1985 study result of a 14 day delay and posited an X-Day on November 16 (though he trims back Marshall's plan of 8-9 nukes in support of MAJESTIC to just 3).
EDIT: Your second post:
Giangreco's book was an interesting read but some of his conclusions I had to wonder about. Like the idea that after reaching the intended stop lines the Americans would be sucked into advancing some kilometres further north in pursuit in the Japanese retreating towards the local redoubt on Kyushu.
I saw that, but I feel reluctant to evaluate it without more study. I am tempted to wonder if it is of a piece with his generally more pessimistic take on DOWNFALL. Perhaps I might say that the willingness of MacArthur to push beyond the stop line might depend on how the fighting had actually progressed, what casualties he had suffered, what the state of Japanese defenses in the area around the stop line was, etc. That said, we all know that MacArthur wasn't averse to jumping past stop lines!