Lifting trough

A colloquial term for an upper-level trough that is weakening, often filling, and moving poleward due to a jet streak on the downstream side of the trough, causing a net export of cyclonic vorticity out of the base of the trough.

Contrast digging trough.

Figure from Midlatitude Synoptic Meteorology: Dynamics, Analysis, and Forecasting by Gary Lackmann, © 2011 Gary Lackmann, published by the American Meteorological Society. Figure originally from Synoptic–Dynamic Meteorology in Midlatitudes: Volume II: Observations and Theory of Weather Systems by Howard B. Bluestein, © 1993 Oxford University Press, Inc. Reproduced with permission of the Licensor through PLSclear.

Term edited 22 December 2021.