The Vertical Cross Section Chart seen in briefings has many useful data points to assist pilots with flight planning. This article described the chart in detail.
Typical Vertical Cross Section Chart.
The top header of the Vertical Cross Section Chart displays the chart name where the weather data was gathered from (in this case Weather Decision Technologies - WDT), the date and time of when the data source was collected, and the time the chart was generated in the briefing.
The chart is always read from left to right like a graph. The left side will show the flight levels from the surface to your highest planned altitude, plus at least 2000 thousand feet.
The bottom of the chart is divided into 15 sections. These sections do not correspond to waypoints on the flight plan. Instead, they evenly divide the entire route into 15 sections.
The Tropopause altitude is displayed on the chart. At the top is a textual description of the Tropopause altitude as a flight level. A red dashed line also shows the Tropopause altitude relative to your flight path.
Direction of Flight
At the top are arrows with a line that bisects the arrow. Those icons represent the direction of North relative to your direction of flight for that leg segment.
North indicators relative to the direction of flight for the leg.
Throughout the chart are wind barbs. They are displayed as wind direction relative to the direction of flight. On the chart, the direction of flight is from left to right.
Wind barbs show the direction of the wind relative to an aircraft traveling left to right.
Barb elements indicate wind speed as follows:
- Short barbs represent 5 knots
- Long barbs represent 10 knots
- Pennants represent 50 knots
Add the barb values to get a wind value. For example, a long and short barb is 15 knots (10 knots + 5 knots = 15 knots). If only a single line is plotted, the winds are calm.
The blue curves with a bisecting line are icing severity indicators. As bisecting lines are added, the icing severity increases. The icing severity icons represent trace, light, moderate, and severe icing.
Icing severity icons.
The colored boxes refer to areas of turbulence. Turbulence coloration is based on the turbulence EDR scale. The scale can be found at the bottom of the chart. Each colored turbulence box displays a turbulence EDR value in the lower right corner.
Areas of turbulence.
Turbulence EDR scale and values in the boxes.
Each box will have a temperature value shown. The temperature is written in degrees Celsius and is a negative value unless prefixed with a plus (+) symbol.
Temperatures are written in degrees negative Celsius.
The highest terrain along your route of flight (+0.1 degree Lat/Long) is shown as a dark-green background in each block.
The terrain is shown in dark green.