Tilted Vertical Structure of a Developing Wave Cyclone

Anticyclone:

• The upper-level high MUST be located south and west of the surface high - i.e., the area of high pressure must tilt to the southwest with height
• An area of convergence MUST be directly above the surface high
• if convergence aloft > divergence at surface, pressure at surface will increase and the high will build (intensify)
• if convergence aloft < divergence at surface, pressure at surface will decrease and the high will decrease in intensity

Storm motion and speed:

• The direction and speed of the cyclone is closely approximated by the speed and direction of the flow at 500mb - referred to as the steering level
  • cyclone moves in direction of 500 mb winds
  • cyclone moves with speed = 1/2 500mb wind speed

The flow aloft appears to be quite important for the development and propagation of cyclones and anticyclones - let's take a closer look......