Rear-inflow jet

From Glossary of Meteorology

rear-inflow jet

A mesoscale circulation feature in which a system-relative current of air enters and flows through the stratiform precipitation region of mesoscale convective systems from the rear.

The rear-inflow jet forms in response to the upshear-tilting of the convective circulation, as the horizontal buoyancy gradients along the back edge of the system create a circulation that draws midlevel air in from the rear. The rear-inflow jet supplies potentially cold and dry midlevel air that aids in the production of convective and system-scale downdrafts.