The Cyclonic Side of Life

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In “The Relativity of the Companion Flows in the Warm Conveyor Belt”  I described the anticyclonic side of the warm conveyor belt found to the right of the central streamline. The warm conveyor belt flow has distinctly different personalities on opposite sides on the dividing streamline that points straight at the col of the deformation zone. The cyclonic companion is found to the left of this dividing line when looking along the direction of the flow.  The streamlines to the left of the divide rise and curl with the fingers of your right hand as they approach the deformation zone skin.  These anticyclonic and cyclonic swirls connect as described before in the “Unified Theory of Swirls”.  But it really helps to look at them separately in a bit more detail to really understand the weather.

The cyclonic side of warm conveyor belt is perhaps the most important in the entire conveyor belt conceptual model. I will explain why. If one follows the atmospheric frame of reference wind direction from the ground in the warm sector of the storm upward while remaining to the left of the dividing streamline and col, your arm initially points from the south. When you mentally rise above the sloped warm frontal surface your arm will turn to more from the southeast. As you continue to climb in your mind, your arm will twist more to pint from the east as it reaches the level of the upstream confluent asymptote of the deformation zone. If you recreate your arm motions with height, your arm twists counter-clockwise or backs with height. Winds backing with height is equivalent to the relative cooling of the atmosphere with height. Relative cooling aloft leads to destabilization of the vertical atmospheric profile. The proverbial hot air balloon will remain warmer than the cooling air at higher heights. This unstable profile keeps the hot air balloon rising. Such an unstable profile has large impacts on the weather and the shapes of the clouds.

Gravity waves are not common in the cyclonic companion. Gravity waves require a stable layer similar to the surface of a lake. The tropopause is the stable lid on the portion of the atmosphere which contains most weather and gravity waves can always be found in the cloud there. Otherwise the clouds to the left of the dividing line of the warm conveyor belt will be more cumulus in nature. The typical cloud types and their locations are indicated in the accompanying graphic.

Note that is typical to observe a minimum in cloud within the delta void adjacent to the col. The amount of moisture being directed into this void actually decreases as the strength of the swirls in the legs of the croquet hoop increases. An intense storm will display an obvious delta void.

Individual layers of moisture are typical at the leading edge of the warm conveyor belt. As the flow continues to direct more moisture and heat energy northward, these discrete layers of moisture will thicken and merge. Precipitation processes commence when the amalgamated cloud thickness exceeds four thousand feet. At this point the integrated cloud layer is called nimbostratus - it is precipitating at the ground.

If the cyclonic side of the warm conveyor belt is sufficiently unstable, convective cloud will continue to boil upward and develop from the cumulus stage into towering cumulus and eventually cumulonimbus or thunderstorms. These unstable clouds can be embedded within the nimbostratus as is typical along the warm front. Lines of convective cloud are also characteristic along the surface cold front.

The engine driving all of this weather on the cyclonic side of the warm conveyor belt is the cyclonic side of the croquet hoop. Moisture and heat is the fuel that feeds the rotation represented by your right hand with the thumb pointing upward. When precipitation processes start, water vapour condenses re-releasing the energy it required to vapourize in the first place. The heat energy powers the rising hot air balloons.  The upward pointing thumb gets bigger more intense which in turn increases the speed of rotation represented by your fingers. In effect the rotation spins up and the cyclonic side of the croquet hoop becomes a large cyclonic tube that extends through the depth of the atmosphere.  One can imagine the prima ballerina or ice skater extending their arms upward and really going for a spin in this atmospheric dance. Moisture bands will wrap around this vorticity tube like tree rings. The number of wraps is directly related to the strength and the age of the vorticity tube.

Further the tilt of this vorticity tube in the vertical reveals the speed of the associated conveyor belt conceptual model relative to the earth. If the tube tilts upward to the east, the storm is moving the same direction as the typical jet stream which moves the weather on average from west to east. The warm conveyor belt will also and will continue to move eastward. The storm will be short-lived at any one location. If the tube tilts upward to the west, the storm will be slow moving or even stationary. The atmospheric frame winds in this case oppose the typical jet stream. Both the duration and intensity of the precipitation are likely to be significant.

I analyzed a specific warm conveyor belt pattern for an artist friend. Note the minimum in the cloud at the col. It illustrates what can be seen from the earth frame of reference. The best place to witness all of these events unfold is through water vapour satellite imagery. The magic of seeing weather evolve through the view from the satellite is where we are headed.

Remember that there is no final exam on any of this material. I present it with the sincere desire that you might enjoy nature as much as I do... we need to work with and support nature. We are all in this together!

Warmest regards and keep your paddle in the water,
Phil the Forecaster