How did Zhuge Liang in Battle of Red Cliffs predict that there would be a southeast wind for three days and three nights?

This is a bit exaggerated and mythical.

According to the study of ancient astronomy, it is possible to have an easterly wind for a period of time. But the east wind only started at a certain moment, lasted for three days and nights, and stopped at a certain moment. Ahem, even now, it is impossible to predict the wind direction.

Anyway, the weather forecast on mobile phone is often invalid.

Therefore, it is a bit of a myth to know that there may be an easterly wind at that time. But the specific time and duration of the east wind is unpredictable.

In the past, some old farmers could really see the weather changes, but they could not make accurate estimates.

There is no doubt that the Three Kingdoms are deified. Of course, this is logically correct. We used the changing wind direction to burn Cao Jun and finally won a great victory. This is a good use of astrometeorology. But it can't be that specific.