Buys Ballot's law

In meteorology, Buys Ballot's law (Dutch pronunciation: [ˌbœy̯s bɑˈlɔt]) may be expressed as follows: In the Northern Hemisphere, if a person stands with their back to the wind, the atmospheric pressure is low to the left, high to the right. This is because wind travels counterclockwise around low pressure zones in the Northern Hemisphere. It is approximately true in the higher latitudes of the Northern Hemisphere, and is reversed in the Southern Hemisphere, but the angle between the pressure gradient force and wind is not a right angle in low latitudes.

A version taught to Naval Cadets in WW2 is: "In the Northern Hemisphere, if you turn your back to the wind, the low pressure center will be to your left and somewhat toward the front." (Aerology for Pilots, McGraw-Hill, 1943, pg 43)