Rear-inflow jet

The rear-inflow jet is a component of bow echoes in a mesoscale convective system that aids in creating a stronger cold pool and downdraft.

In response to the surface high and warmer temperatures aloft due to convection, a mid-level mesolow forms behind the leading edge of the storm.

Before reaching the leading edge, the jet descends to the surface as a strong downdraft, creating straight-line winds.

[2][3] The sinking of the jet first starts when the mid level inflow goes under the trailing stratiform cloud before descending to the melting layer.

The other factor that can help strengthen the jet is an environment in which the large scale flow is feeding/forcing mid-level air into the rear end of the storm.

Conceptual airflow in a squall line with the Rear-inflow jet shown
Rear-inflow notch caused by the sinking of the jet behind a bow echo line