EZTip No. 11 - EZRoute Profile view for turbulence
There are a few things to consider when you are looking at the EZRoute Profile view 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. Green is used for light turbulence, brown/tan is used for moderate turbulence and red is severe turbulence as shown below (dark red is not shown, but represents extreme turbulence). If there's no color shown, this means that the turbulence is expected to be negligible or null.
You can tap on a rectangle when on a touch screen device or using a mouse hover your cursor over the rectangle to see the specific EDR value. In the case below, the cursor is hovered over the red rectangle and the EDR value is 37. Severe turbulence for light aircraft begins at 36.
You will want to verify that your aircraft weight class is set properly in the EZSettings. Most EZWxBrief users will set their aircraft weight class to Light (which is also the default) as shown below. 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 EZRoute 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 EZWxBrief Pilots Guide for more information).
Please understand that this color-coded profile is independent of how you have set your EZMinimums for turbulence intensity as shown below. Again, the colors shown in the EZRoute Profile above are mapped to industry-accepted values as documented by researchers in this industry. Therefore, you may want to set your personal weather minimums to values that correspond directly to your own personal risk tolerance.
In the EZMinimums, the number on the left (16 in the example on 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.
Interested in learning more about the Skew-T? You can order your copy of The Skew-T log (p) and Me eBook today.
Most pilots are weatherwise, but some are otherwiseâ„¢
Dr. Scott Dennstaedt
Weather Systems Engineer
Founder, EZWxBriefâ„¢
CFI & former NWS meteorologist
