The scenario needs a credible observer who can report the carrier force without immediately alerting it, because Japanese orders called for withdrawal if surprise was lost. The northern route was selected to thread gaps between American search coverage and routine maritime traffic. Japanese planners also treated published American aircraft ranges conservatively, giving patrol bases an even wider berth than the stated figures alone required. A storm on 4 December creates the narrow opportunity: it restricts Japanese flying while offering cloud cover to a scout aircraft.
Chapter · 5:31-10:15
Why the Kido Butai was so difficult to discover
The Japanese approach route deliberately avoids patrol areas, shipping lanes, fishing traffic, and other likely sources of detection.