Reference: USAFETAC/TN--92/004, PAG: 2-37
As in the Northern Hemisphere, Southern Hemisphere extratropical cyclones/troughs follow a west-to-east trajectory.
Polar troughs are cold core systems, with cyclonic vorticity increasing with height.
- Cyclonic circulation is clockwise (Negative Vorticity)
- Anticyclonic circulation is counter clockwise (Positive Vorticity)
In preparation for this module, forecasters/meteorologists need to first review USAFETAC/TN--92/004, PAG: 2-37 to 2-66
Forecasters working the Southern and Northern Hemispheres should avoid using positive vorticity advection (PVA) and negative vorticity advection (NVA). Instead, forecasters and meteorologists should use cyclonic vorticity advection and anticyclonic vorticity advection.