Cyclonic scale

From Glossary of Meteorology

cyclonic scale

(Also called synoptic scale.) The scale of the migratory high and low pressure systems (or cyclone waves) of the troposphere with wave lengths of 1000–4000 km.

Terminology in the literature is confusing, chiefly because cyclonic-scale disturbances at low levels are frequently associated with large-scale disturbances in the high troposphere.
See barotropic instability, baroclinic instability.