Looks Confusing, What Is It?

This is what meteorologists call a "300 millibar map." It helps us forecast by providing a view of what's going on in the higher reaches of the atmosphere. The white lines are called "height lines." They tell us at what height in the atmosphere we reach 300 millibars of pressure. The different colors on the map represent different wind speeds in the upper atmosphere. On this map, the purples and blues are the slowest speeds and the greens are the fastest. The fastest winds compose what is called the jet stream, or the highway of winds that guides storms across the country.

Jonathan Myers