Overview

Vorticity Minima and Anticomma Patterns

Season: Every day

Phenomena: Dry Circulation, Vorticity Minima, and Vertical Velocity

Tools: GOES water vapour

Forecast Challenges:

  • Identify and predict vorticity minima in order to predict areas of negative vorticity advection
  • Identify the related axes of maximum winds, shear zones, deformation zones, and air masses

Vorticity minima signatures are every bit as common as vorticity maxima signatures. They indicate areas of descending circulation and atmospheric forcing and can be used to diagnose dynamic features such as the axis of maximum winds and deformation zones.

Note: All examples and conceptual models in this module are set in the northern hemisphere. All graphics are oriented north to south with north on top.

GOES Water Vapor, 1030 UTC  27 Jul 05 showing a typical anticomma pattern with pattern highlighted.
GOES Water Vapor, 1030 UTC  27 Jul 05 showing a typical anticomma pattern.