As we approach the heart of summer and the heart of baseball season, it is interesting how a small change in the weather can make a huge different in the game.
Whether you are a Cardinals fan or Royals fan, a few degrees difference on the thermometer or a little more moisture in the air can mean the difference in between a fly ball caught in center field and a long ball that lands in the bleachers.
There are many different variables meteorologists measure in the atmosphere: temperatures, humidity, pressure and wind are some examples. Some of these variables are listed below and an explanation of how they impact a baseball.
Pressure: In atmospheric science, pressure is dependent on elevation. At higher elevations, air becomes less dense than air closer to the surface. When air is less dense, a baseball will fly further. The reason is there is less friction acting on the baseball. The air creates a frictional force that acts on the baseball as it travels through the air and touches the ball. The smaller the frictional force, the faster and further it will travel. This is the same effect that you would see if you were sliding a box along a hardwood floor and onto carpet. There is more friction with the carpet and it makes it harder to slide that box.
Temperature: As air warms, it expands. This expansion of the air causes it??s density to lower because there are less air molecules in the same volume of air ?? meaning there are less air molecules (causing friction) to slow down the ball.
Moisture (Humidity): The higher humidity the less dense the air is. Now, I bet some of you are going to ask, ??If there is more moisture in the air, isn??t there more molecules to cause friction and slow down there ball??? The answer to that is no.
The reason that moist air is less dense is because the amount of water vapor in the air also affects the density. Water vapor (which chemical formula is H2O) is lighter when compared to the other two most abundant gases that make up the atmosphere: Nitrogen (N2) and Oxygen (O2). When looking at their weights on a molecular level, H20 has a weight of 18 (1+1+16) atomic units, N2 has a weight of 28 (14+14) atomic units and O2 has a weight of 32 (16+16) atomic units. This means Nitrogen and Oxygen are much heavier than water vapor at constant temperature, pressure and volume
.Moist air, composed mostly of H20, has a weight of 18, while dry air, which is composed mostly of nitrogen and oxygen has a weight of 60. Putting this all together it comes down to this: The more mass (in this case atomic mass) you have in a constant volume in the atmosphere, the more dense it will be.
Wind: Wind can either reduce or enhance the amount of friction a baseball feels when it is in motion. Air flow toward a baseball puts more friction on it which will slow the ball. On the flip side, air moving with the ball will help to propel it further ?? hopefully for a home run!
So, what is the ideal forecast for that perfect home run?
Higher elevation (like Coors field in Denver, CO), wind blowing out toward the outfield and a warm and humid air mass.
If you are a pitcher and you want to keep the baseball inside the ball park, the ideal forecast would be low elevation, wind blowing in from the outfield and a cold and dry air mass.