How does air pressure affect the weather?

Have you ever wondered how air pressure affects the weather around you?

Before hurricanes could be spotted by satellites from space, people would keep a wary eye on their barometers during hurricane season. If the air pressure dropped, that was usually a good time to board up windows and head further inland!

As hurricanes pass over coastal areas, air pressure can drop significantly. At sea level air pressure is normally around 1013.25mb (29.92 inches of mercury). Extremely strong hurricanes are accompanied by air pressure drops of between 30 and 70mb. The greater the pressure difference between a low pressure area and a high pressure area, the stronger the winds! Wind is the natural result of having a low pressure area next to a higher pressure area since the air molecules in the higher pressure zone will migrate to the "more spacious" surroundings of the low pressure area.

Tornadoes, also known as Twisters, can be as destructive as hurricanes on a smaller scale. A falling barometer can indicate bad weather approaching and many people in the midwest and central plains states will head into the cellar when the air pressure drops dramatically. Tornadoes account for millions of dollars of damage and significant human suffering in the U.S. each year. Because of this, many scientists are studying the way in which tornadoes form and how they behave. 

If you have any questions, don’t hesitate to get in touch.