Does the direction a flag waves tell generally where the high and low pressure centers are?
In general terms, it does. In 1857, Buys Ballot, a Dutch meteorologist, formulated a law describing the relationship between wind direction and air pressure distribution. In the Northern Hemisphere where the wind circulation is counterclockwise around low pressure and clockwise around high pressure, the Buys Ballot law states that if a person stands with their back to the wind, the air pressure to the left is lower than the pressure to the right. Therefore, a person facing north with a south wind at their back would find lower pressure to the left or west and higher pressure to the right or east. This relationship reversed in the Southern Hemisphere.