Definition

The synoptic scale is the spatial scale of the migratory high and low pressure systems of the lower troposphere, with wavelengths of 1,000 to 2,500 km. (U.S. National Oceanic and Atmospheric Administration)

Description

Synoptic means "view together" or "view at a common point." Synoptic meteorology means viewing the weather across a large scale at a common point in time. This helps identify patterns such as areas of high and low pressure, warm and cold fronts, and extratropical cyclones and their associated fronts. Charts produced in this manner include surface weather analysis charts.

Meteorology across smaller scales includes:

• Mesoscale meteorology: The study of weather systems at horizontal scales of five to several hundred kilometers.
• Microscale meteorology: The study of short-lived weather systems at horizontal scales of one kilometer or less.
• Misoscale meteorology: The study of weather phenomena at horizontal scales of 40 meters to about four kilometers. 

The misoscale was proposed by meteorologist Ted Fujita to examine brief events such as microbursts or rotation inside a thunderstorm. By contrast, synoptic scale weather features have a time span of a few days to a week or more.