The Relativity of the Companion Flows in the Warm Conveyor Belt

#1713 "December Morn" Pixels Link

Trying to measure the absolute value of anything is a challenge. One would require access to the entire data set which is often simply impossible.  Climate change is one example of this. Forecasting COVID-19 is another…

But everything is relative in nature. In the natural world we can compare and comparatively better understand the nature around us without measuring the entire globe. The warm conveyor belt offers a great opportunity to do just that.

I have been presenting the warm conveyor belt as a single entity. In reality the warm conveyor belt has a split personality and it is vitally important to know both sides. The companion vortices described in the three dimensional smoke rings are shaped by their companion flows. The dividing line is the streamline that follows the centre of the warm conveyor belt flow and points straight at the col. Looking along the direction of the flow, the streamlines to the right of the divide rise and curl anticyclonically as they approach the deformation zone skin.  Streamlines to the left of the divide rise and swirl cyclonically as they near the deformation zone. These swirls connect as described before in the “Unified Theory of Swirls”. But it really helps to look at them in a bit more detail to better understand the weather.

When in forecast operations, I used my hands to better visualize air flows and the conceptual models that applied to a given weather concern of the day. I used my right hand a lot and did a considerable amount of arm waving in trying to better explain the processes. That was before PowerPoint and the fantastic graphic artists and animators of COMET.  In those early days meteorology was kind of like break-dancing without anything getting broken. I had wished that more of my fellow meteorologists had joined in the dance but I probably didn’t explain the science well enough. The workload was heavy and there were simpler ways to produce a forecast. Meteorologists were drowning in data anyway with the burgeoning numerical modelling and statistical approaches to weather prediction. My approach was to simplify the atmosphere by putting the data into the context of conceptual models and satellite imagery.  But I digress… let’s look at the anticyclonic companion in the warm conveyor belt.

If one follows the atmospheric frame of reference wind direction from the ground up to the right of the col, your arm initially points from the northeast in the cold conveyor belt. Winds are named by the direction they blow from. When you mentally reach the level of the elevated warm front, your arm will point more from the southeast. As you continue to climb in your mind, your arm will turn more to the south and then to the west or northwest as it reaches the level of the downstream confluent asymptote of the deformation zone. If you recreate your arm motions with height, your arm turns clockwise or veers with height. Winds veering with height is equivalent to the relative warming of the atmosphere with height. This leads to stabilization of the vertical profile. The proverbial hot air balloon will encounter warm air at higher heights and stop rising. This profile has large impacts on the weather and the shapes of the clouds. The typical clouds found in in the stable atmosphere of the anticyclonic companion branch are named and located in the accompanying graphic.

Gravity waves are common in the anticyclonic companion. Gravity waves require a stable layer to develop. These cloud waves are everywhere perpendicular to the winds in the atmosphere. Like waves on a lake, the size and distance between the cloud crests increase with the wind speed. The size and the spacing of the three white bars in the graphic are intended to represent the gravity waves superimposed on the described cloud types. Gravity waves are also your best friends when you want to witness the relative wind directions in the atmosphere.


A picture can save a lot of words and I have included a few graphics to better explain what to look for in the anticyclonic companion branch of the warm conveyor belt.

The other way to try to discern the atmospheric wind is to simply line up a cloud element with something that is not moving and watch it move. The problem with this approach is that the average motion of the atmosphere is added to the winds measured relative to the atmosphere itself. Your single view does not contain all of the data required to calculate the average wind that is translating your clouds. The earth frame observed wind can be ambiguous and difficult to understand in terms of a simple conceptual model like the Conveyor Belt Conceptual Model as pictured. As a start though one can assume that storm motion has a component both from the south and the west and that average wind is blowing the Conveyor Belt Conceptual Model along. Operationally I used satellite imagery to calculate the average speed of translation over the area of weather that I was concerned about.

I also observed this meteorology while paddling and painting.  Just a few examples that I remember are #1713 "December Morn" as pictured at the start of this post, #1908 "Cirrious Stories" and #1928 "Turtle Rock McCrae". There are many more in my portfolio of 2350 paintings and counting...

There is no final exam on any of this stuff. I present it with the sincere hope that you might enjoy nature as much as I do...

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

PS: Much more to come and thank you to my COMET friends in Boulder who helped to publish some of this stuff.