EZTip - Route Profile view for turbulence

There are a few things to consider when you are looking at the Route Profile view or meteogram for turbulence. The view you see is categorically colored-coded based on the industry-accepted eddy dissipation rate (EDR) values for Light, Medium and Heavy aircraft shown in the table below (note that EDR is multiplied by 100 to make it a whole number instead of a fraction). Green is used for light turbulence (EDR of 13-15), brown/tan is used for moderate turbulence (EDR of 16-34) and red is severe turbulence (EDR of 36-63) as shown below (dark red is not shown, but represents extreme turbulence or EDR of 64 or greater). If there's no color shown, this means that the turbulence is expected to be negligible or null (EDR value of 12 or less).

You can tap on the profile view when using a touch screen device or hover over the view with the cursor when using a mouse to see the specific EDR value. In the case above, the cursor is hovered over the red rectangle and the EDR value is 37. Severe turbulence for light aircraft begins with an EDR of 36 as shown in the table below

You will want to verify that your aircraft weight class is set properly in the Aircraft Settings. Most EZWxBrief users will set their aircraft weight class to Light (which is also the default) as shown to the left. Of course, we know that heavier aircraft respond differently than lighter aircraft when exposed to the same EDR value. For example, flying in a Cirrus SR22 with an EDR value of 18 will likely be moderate, but in a Boeing 737 it will be light. So given any particular route, you will see a different rendering of the colors based on the aircraft class chosen.

At this time, this aircraft weight class setting is only used by EZWxBrief to determine how to color-code the Route Profile view like the one shown above. This is based on the accepted EDR thresholds for the turbulence categories based on weight class (see the table below or the EZWxBrief Pilots Guide for more information).

Please understand that this color-coded profile is independent of how you have set your Personal Minimums for turbulence intensity as shown below. Again, the colors shown in the Route Profile are mapped to industry-accepted values as documented by turbulence researchers in this industry and accepted by the NWS/FAA. Therefore, you may want to set your personal weather minimums to values that correspond directly to your own personal risk tolerance.

In the Personal Minimums, the number on the left (16 in the example to the right) is the conservative personal minimum. That is, when the EDR value along the proposed route of flight and chosen altitude is 16 or less, this is considered a low risk situation. On the other hand, the value on the right is the actual personal weather minimum (36 in this case). If the weather along the proposed route of flight and altitude is greater than or equal this value, then this would be considered a high risk. For some pilots, an EDR value of 36 (which is considered severe) may be extremely uncomfortable and you might want to set this lower to warn you about the potential of turbulence that is outside your personal comfort level.

Most pilots are weatherwise, but some are otherwise™

Dr. Scott Dennstaedt

Weather Systems Engineer

Founder, EZWxBrief™

CFI & former NWS meteorologist