Most pilots (if not all!) will be familiar with the humble Synopic Chart. Where similar points of pressure are joined with lines, so you can visually get a sense of what is happening in the atmosphere. Another example of this style of chart would be the contour lines on a topographic map.
In the latest version of AvPlan EFB, we take this concept and apply it to another important consideration for pilots: Freezing Level. All AvPlan EFB subscribers can access this new overlay.
To turn it on, tap the RADAR icon in the top-right of the En Route pane, then select Freezing Level Forecast.
The overlay will then look something like this:
Lets have a look at what it is displaying to us.
The numbers represent the freezing level in feet Above Mean Sea Level (AMSL). The lines join similar levels. The closer the lines are, the sharper the temperature drop off is.
The other advantage of this display is being able to project many hours in the future.
Use the controls that appear at the bottom of the map to step through the various snapshots of the mathematical model. You can move through to around 60 hours into the future. The play button will animate through each frame automatically.
Remember: This layer can be overlaid on top of any map.
To turn it off again, tap the RADAR icon and deselect Freezing Level Forecast.
Add this to your own pre-flight self briefing.