Digging trough

A colloquial term for an upper-level trough that is amplifying, often deepening, and pushing equatorward due to a jet streak on the upstream side of the trough, causing a net import of cyclonic vorticity into the base of the trough.

Contrast lifting 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.

Bluestein, H. B., 1993. Synoptic–Dynamic Meteorology in Midlatitudes: Volume II, Observations and Theory of Weather Systems. Oxford University Press, 594 pp.

Lackmann, G., 2011. Midlatitude Synoptic Meteorology: Dynamics, Analysis, and Forecasting. American Meteorological Society, 360 pp.

Term edited 26 February 2024.