Meteorologists divide weather patterns and motions based on actions that are occurring at various scales of size. Just as economists have macroeconomics (how the economy functions on a regional, national, or international level) and microeconomics (financial concepts applied to a single household or business), meteorologists find it convenient to divide weather phenomena this way, too. Below is an explanation of the divisions.

• The macroscale (or synoptic scale) refers to weather processes affecting large areas, such as pressure systems, fronts, and the jet stream.

• The microscale concerns highly localized events, such as a tornado, a fog bank, or a small rain shower that affects an area of only a few hundred square feet or meters.

• The mesoscale deals with weather events somewhere between the micro and macro levels, usually ranging over several miles to a hundred miles or so. Thunderstorms, cloud systems, and breeze fronts are some examples of weather falling into this category. The mesoscale is sometimes divided even further into 1) meso-gamma (covering about 1 to 12 miles [2 to 20 kilometers]), 2) meso-beta (25 to 125 miles [20 to 200 kilometers]), and 3) meso-alpha (125 to 1,250 miles [200 to 2,000 kilometers]).