the four meteorological scales

The scale of weather and climate phenomena vary greatly, from the small-scale mixing of air pollution over a power plant to the global-scale westerlies flowing across the midlatitudes (a reminder that westerlies move from the west to the east...not the most intuitive naming convention, if you ask me!).

We can divide meteorological motion into a set of four scales, based on horizontal length and time. From smallest to largest, these scales are the microscale, mesoscale, synoptic scale, and planetary scale.